domain
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difficulty
float64
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solution
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answer
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source
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[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
If $3+x=5$ and $-3+y=5$, what is the value of $x+y$?
Since $3+x=5$, then $x=2$. Since $-3+y=5$, then $y=8$. Thus, $x+y=10$. Alternatively, we could have added the original two equations to obtain $(3+x)+(-3+y)=5+5$ which simplifies to $x+y=10$.
10
fermat
[ "Mathematics -> Applied Mathematics -> Statistics -> Probability -> Counting Methods -> Combinations" ]
1.5
The set $S=\{1,2,3, \ldots, 49,50\}$ contains the first 50 positive integers. After the multiples of 2 and the multiples of 3 are removed, how many integers remain in the set $S$?
The set $S$ contains 25 multiples of 2 (that is, even numbers). When these are removed, the set $S$ is left with only the odd integers from 1 to 49. At this point, there are $50-25=25$ integers in $S$. We still need to remove the multiples of 3 from $S$. Since $S$ only contains odd integers at this point, then we must remove the odd multiples of 3 between 1 and 49. These are $3,9,15,21,27,33,39,45$, of which there are 8. Therefore, the number of integers remaining in the set $S$ is $25-8=17$.
17
pascal
[ "Mathematics -> Geometry -> Plane Geometry -> Polygons" ]
1
If the perimeter of a square is 28, what is the side length of the square?
Since a square has four equal sides, the side length of a square equals one-quarter of the perimeter of the square. Thus, the side length of a square with perimeter 28 is $28 \div 4 = 7$.
7
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1
Erin walks $\frac{3}{5}$ of the way home in 30 minutes. If she continues to walk at the same rate, how many minutes will it take her to walk the rest of the way home?
Since Erin walks $\frac{3}{5}$ of the way home in 30 minutes, then she walks $\frac{1}{5}$ of the way at the same rate in 10 minutes. She has $1-\frac{3}{5}=\frac{2}{5}$ of the way left to walk. This is twice as far as $\frac{1}{5}$ of the way. Since she continues to walk at the same rate and $\frac{1}{5}$ of the way takes her 10 minutes, then it takes her $2 \times 10=20$ minutes to walk the rest of the way home.
20
pascal
[ "Mathematics -> Geometry -> Plane Geometry -> Polygons" ]
1
Points with coordinates $(1,1),(5,1)$ and $(1,7)$ are three vertices of a rectangle. What are the coordinates of the fourth vertex of the rectangle?
Since the given three points already form a right angle, then the fourth vertex of the rectangle must be vertically above the point $(5,1)$ and horizontally to the right of $(1,7)$. Therefore, the $x$-coordinate of the fourth vertex is 5 and the $y$-coordinate is 7. Thus, the coordinates of the fourth vertex are $(5,7)$.
(5,7)
pascal
[ "Mathematics -> Number Theory -> Least Common Multiples (LCM)" ]
1.5
What is the smallest positive integer that is a multiple of each of 3, 5, 7, and 9?
Since 9 is a multiple of 3, every positive integer that is a multiple of 9 is also a multiple of 3. The smallest positive integer that is a multiple of each of 7 and 9 is 63. The smallest multiple of 63 that is also a multiple of 5 is 315.
315
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Fractions" ]
1.5
What is the smallest integer that can be placed in the box so that $\frac{1}{2} < \frac{\square}{9}$?
We know that $\frac{1}{2} = 0.5$. Since $\frac{4}{9} \approx 0.44$ is less than $\frac{1}{2} = 0.5$, then 4 cannot be placed in the box. (No integer smaller than 4 can be placed in the box either.) Since $\frac{5}{9} \approx 0.56$ is greater than $\frac{1}{2} = 0.5$, then the smallest integer that can be placed in the box is 5.
5
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Decimals" ]
1
What is the value of the expression \( 4 + \frac{3}{10} + \frac{9}{1000} \)?
Converting from fractions to decimals, \( 4 + \frac{3}{10} + \frac{9}{1000} = 4 + 0.3 + 0.009 = 4.309 \).
4.309
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
Mike rides his bicycle at a constant speed of $30 \mathrm{~km} / \mathrm{h}$. How many kilometres does Mike travel in 20 minutes?
Since 1 hour equals 60 minutes, then 20 minutes equals $\frac{1}{3}$ of an hour. Since Mike rides at $30 \mathrm{~km} / \mathrm{h}$, then in $\frac{1}{3}$ of an hour, he travels $\frac{1}{3} \times 30 \mathrm{~km}=10 \mathrm{~km}$.
10
fermat
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
Calculate the value of the expression $\frac{1+(3 \times 5)}{2}$.
Using the correct order of operations, $\frac{1+(3 \times 5)}{2}=\frac{1+15}{2}=\frac{16}{2}=8$.
8
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
Many of the students in M. Gamache's class brought a skateboard or a bicycle to school yesterday. The ratio of the number of skateboards to the number of bicycles was $7:4$. There were 12 more skateboards than bicycles. How many skateboards and bicycles were there in total?
Since the ratio of the number of skateboards to the number of bicycles was $7:4$, then the numbers of skateboards and bicycles can be written in the form $7k$ and $4k$ for some positive integer $k$. Since the difference between the numbers of skateboards and bicycles is 12, then $7k - 4k = 12$ and so $3k = 12$ or $k = 4$. Therefore, the total number of skateboards and bicycles is $7k + 4k = 11k = 11 \times 4 = 44$.
44
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
What is the result of subtracting eighty-seven from nine hundred forty-three?
Converting to a numerical expression, we obtain $943-87$ which equals 856.
856
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Fractions" ]
1
What is the smallest integer that can be placed in the box so that $\frac{1}{2} < \frac{\square}{9}$?
We know that $\frac{1}{2} = 0.5$. Since $\frac{4}{9} \approx 0.44$ is less than $\frac{1}{2} = 0.5$, then 4 cannot be placed in the box. (No integer smaller than 4 can be placed in the box either.) Since $\frac{5}{9} \approx 0.56$ is greater than $\frac{1}{2} = 0.5$, then the smallest integer that can be placed in the box is 5.
5
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1.5
If \(3 \times 3 \times 5 \times 5 \times 7 \times 9 = 3 \times 3 \times 7 \times n \times n\), what is a possible value of \(n\)?
Since \(3 \times 3 \times 5 \times 5 \times 7 \times 9 = 3 \times 3 \times 7 \times n \times n\), then \(n \times n = \frac{3 \times 3 \times 5 \times 5 \times 7 \times 9}{3 \times 3 \times 7} = 5 \times 5 \times 9 = 5 \times 5 \times 3 \times 3\). Since \(n \times n = 5 \times 5 \times 3 \times 3\), then a possible value for \(n\) is \(n = 5 \times 3 = 15\).
15
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
What is the value of the expression $2 \times 3 + 2 \times 3$?
Evaluating, $2 \times 3 + 2 \times 3 = 6 + 6 = 12$.
12
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Sequences -> Other" ]
1.5
Ewan writes out a sequence where he counts by 11s starting at 3. The resulting sequence is $3, 14, 25, 36, \ldots$. What is a number that will appear in Ewan's sequence?
Ewan's sequence starts with 3 and each following number is 11 larger than the previous number. Since every number in the sequence is some number of 11s more than 3, this means that each number in the sequence is 3 more than a multiple of 11. Furthermore, every such positive integer is in Ewan's sequence. Since $110 = 11 \times 10$ is a multiple of 11, then $113 = 110 + 3$ is 3 more than a multiple of 11, and so is in Ewan's sequence.
113
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
Seven students shared the cost of a $\$26.00$ pizza. Each student paid either $\$3.71$ or $\$3.72$. How many students paid $\$3.72$?
We can rephrase the given information by saying that each of the seven students paid $\$3.71$ and some of the students paid an extra $\$0.01$. Since $7 \times \$3.71=\$25.97$ and the pizza cost $\$26.00$ in total, then the students who paid the extra $\$0.01$ each must make up the final $\$0.03$ of the cost of the pizza. Therefore, 3 students each paid an additional $\$0.01$ and so paid $\$3.72$ in total.
3
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1.5
What is the median of the numbers in the list $19^{20}, \frac{20}{19}, 20^{19}, 2019, 20 \times 19$?
Since $\frac{20}{19}$ is larger than 1 and smaller than 2, and $20 \times 19 = 380$, then $\frac{20}{19} < 20 \times 19 < 2019$. We note that $19^{20} > 10^{20} > 10000$ and $20^{19} > 10^{19} > 10000$. This means that both $19^{20}$ and $20^{19}$ are greater than 2019. In other words, of the five numbers $19^{20}, \frac{20}{19}, 20^{19}, 2019, 20 \times 19$, the third largest is 2019. Since the list contains 5 numbers, then its median is the third largest number, which is 2019.
2019
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
If $\sqrt{n+9}=25$, what is the value of $n$?
Since $\sqrt{n+9}=25$, then $n+9=25^{2}=625$. Thus, $n=625-9=616$.
616
fermat
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
If $2x + 6 = 16$, what is the value of $x + 4$?
Solution 1: Since $2x + 6 = 16$, then $\frac{2x + 6}{2} = \frac{16}{2}$ and so $x + 3 = 8$. Since $x + 3 = 8$, then $x + 4 = (x + 3) + 1 = 8 + 1 = 9$. Solution 2: Since $2x + 6 = 16$, then $2x = 16 - 6 = 10$. Since $2x = 10$, then $\frac{2x}{2} = \frac{10}{2}$ and so $x = 5$. Since $x = 5$, then $x + 4 = 5 + 4 = 9$.
9
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
A hockey team has 6 more red helmets than blue helmets. The ratio of red helmets to blue helmets is $5:3$. What is the total number of red helmets and blue helmets?
Suppose that the team has $r$ red helmets. Since the team has 6 more red helmets than blue helmets, then the team has $r-6$ blue helmets. Since the ratio of the number of red helmets to the number of blue helmets is $5:3$, then $\frac{r}{r-6}=\frac{5}{3}$ and so $3r=5(r-6)$ or $3r=5r-30$. Therefore, $2r=30$ or $r=15$. Thus, the team has 15 red helmets, 9 blue helmets, and $15+9=24$ helmets in total.
24
pascal
[ "Mathematics -> Geometry -> Plane Geometry -> Polygons" ]
1.5
Two circles are centred at the origin. The point $P(8,6)$ is on the larger circle and the point $S(0, k)$ is on the smaller circle. If $Q R=3$, what is the value of $k$?
We can determine the distance from $O$ to $P$ by dropping a perpendicular from $P$ to $T$ on the $x$-axis. We have $O T=8$ and $P T=6$, so by the Pythagorean Theorem, $O P^{2}=O T^{2}+P T^{2}=8^{2}+6^{2}=64+36=100$. Since $O P>0$, then $O P=\sqrt{100}=10$. Therefore, the radius of the larger circle is 10. Thus, $O R=10$. Since $Q R=3$, then $O Q=O R-Q R=10-3=7$. Therefore, the radius of the smaller circle is 7. Since $S$ is on the positive $y$-axis and is 7 units from the origin, then the coordinates of $S$ are $(0,7)$, which means that $k=7$.
7
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
When two positive integers are multiplied, the result is 24. When these two integers are added, the result is 11. What is the result when the smaller integer is subtracted from the larger integer?
The positive divisor pairs of 24 are: 1 and 24, 2 and 12, 3 and 8, 4 and 6. Of these, the pair whose sum is 11 is 3 and 8. The difference between these two integers is $8 - 3 = 5$.
5
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
Hagrid has 100 animals. Among these animals, each is either striped or spotted but not both, each has either wings or horns but not both, there are 28 striped animals with wings, there are 62 spotted animals, and there are 36 animals with horns. How many of Hagrid's spotted animals have horns?
Each of the animals is either striped or spotted, but not both. Since there are 100 animals and 62 are spotted, then there are $100 - 62 = 38$ striped animals. Each striped animal must have wings or a horn, but not both. Since there are 28 striped animals with wings, then there are $38 - 28 = 10$ striped animals with horns. Each animal with a horn must be either striped or spotted. Since there are 36 animals with horns, then there are $36 - 10 = 26$ spotted animals with horns.
26
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
The list $p, q, r, s$ consists of four consecutive integers listed in increasing order. If $p + s = 109$, what is the value of $q + r$?
Since $p, q, r, s$ is a list of consecutive integers in increasing order, then $q$ is 1 more than $p$ and $r$ is 1 less than $s$. This means that $q + r = (p + 1) + (s - 1) = p + s = 109$. Therefore, $q + r = 109$.
109
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1.5
The list $p, q, r, s$ consists of four consecutive integers listed in increasing order. If $p + s = 109$, what is the value of $q + r$?
Since $p, q, r, s$ is a list of consecutive integers in increasing order, then $q$ is 1 more than $p$ and $r$ is 1 less than $s$. This means that $q + r = (p + 1) + (s - 1) = p + s = 109$. Therefore, $q + r = 109$.
109
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1
At what time did Kamal turn his computer off if he turned it on at 2 p.m. on Friday and left it on for exactly 30 consecutive hours?
We need to determine the time that is 30 hours after 2 p.m. on Friday. The time that is 24 hours after 2 p.m. on Friday is 2 p.m. on Saturday. The time that is 30 hours after 2 p.m. on Friday is an additional 6 hours later. This time is 8 p.m. on Saturday.
8 \text{ p.m. on Saturday}
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
What is the value of $k$ if the side lengths of four squares are shown, and the area of the fifth square is $k$?
Let $s$ be the side length of the square with area $k$. The sum of the heights of the squares on the right side is $3+8=11$. The sum of the heights of the squares on the left side is $1+s+4=s+5$. Since the two sums are equal, then $s+5=11$, and so $s=6$. Therefore, the square with area $k$ has side length 6, and so its area is $6^{2}=36$. In other words, $k=36$.
36
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
What is the value of \( \frac{2018-18+20}{2} \)?
Evaluating, \( \frac{2018-18+20}{2} = \frac{2000+20}{2} = \frac{2020}{2} = 1010 \).
1010
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
An electric car is charged 3 times per week for 52 weeks. The cost to charge the car each time is $0.78. What is the total cost to charge the car over these 52 weeks?
Since the car is charged 3 times per week for 52 weeks, it is charged \(3 \times 52 = 156\) times. Since the cost per charge is $0.78, then the total cost is \(156 \times 0.78 = 121.68\).
\$121.68
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
In a number line, point $P$ is at 3 and $V$ is at 33. The number line between 3 and 33 is divided into six equal parts by the points $Q, R, S, T, U$. What is the sum of the lengths of $PS$ and $TV$?
The segment of the number line between 3 and 33 has length $33 - 3 = 30$. Since this segment is divided into six equal parts, then each part has length $30 \div 6 = 5$. The segment $PS$ is made up of 3 of these equal parts, and so has length $3 \times 5 = 15$. The segment $TV$ is made up of 2 of these equal parts, and so has length $2 \times 5 = 10$. Thus, the sum of the lengths of $PS$ and $TV$ is $15 + 10$ or 25.
25
pascal
[ "Mathematics -> Applied Mathematics -> Statistics -> Probability -> Other" ]
1.5
Ben participates in a prize draw. He receives one prize that is equally likely to be worth $\$5, \$10$ or $\$20$. Jamie participates in a different prize draw. She receives one prize that is equally likely to be worth $\$30$ or $\$40$. What is the probability that the total value of their prizes is exactly $\$50$?
Since there are two possible prizes that Jamie can win and each is equally likely, then the probability that Jamie wins $\$30$ is $\frac{1}{2}$ and the probability that Jamie wins $\$40$ is $\frac{1}{2}$. If Jamie wins $\$30$, then for the total value of the prizes to be $\$50$, Ben must win $\$20$. The probability that Ben wins $\$20$ is $\frac{1}{3}$, since there are three equally likely outcomes for Ben. If Jamie wins $\$40$, then for the total value of the prizes to be $\$50$, Ben must win $\$10$. The probability that Ben wins $\$10$ is $\frac{1}{3}$. Since Ben's and Jamie's prizes come from different draws, we can assume that the results are independent, and so the probability that Jamie wins $\$30$ and Ben wins $\$20$ is $\frac{1}{2} \times \frac{1}{3} = \frac{1}{6}$. Similarly, the probability that Jamie wins $\$40$ and Ben wins $\$10$ is $\frac{1}{2} \times \frac{1}{3} = \frac{1}{6}$. Therefore, the probability that the total value of their prizes is $\$50$ is $\frac{1}{6} + \frac{1}{6} = \frac{1}{3}$.
\frac{1}{3}
pascal
[ "Mathematics -> Algebra -> Algebra -> Equations and Inequalities" ]
1.5
What is the sum of all of the possibilities for Sam's number if Sam thinks of a 5-digit number, Sam's friend Sally tries to guess his number, Sam writes the number of matching digits beside each of Sally's guesses, and a digit is considered "matching" when it is the correct digit in the correct position?
We label the digits of the unknown number as vwxyz. Since vwxyz and 71794 have 0 matching digits, then $v \neq 7$ and $w \neq 1$ and $x \neq 7$ and $y \neq 9$ and $z \neq 4$. Since vwxyz and 71744 have 1 matching digit, then the preceding information tells us that $y=4$. Since $v w x 4 z$ and 51545 have 2 matching digits and $w \neq 1$, then $v w x y z$ is of one of the following three forms: $5 w x 4 z$ or $v w 54 z$ or $v w x 45$. Case 1: vwxyz $=5 w x 4 z$ Since $5 w x 4 z$ and 21531 have 1 matching digit and $w \neq 1$, then either $x=5$ or $z=1$. If $x=5$, then $5 w x 4 z$ and 51545 would have 3 matching digits, which violates the given condition. Thus, $z=1$. Thus, $v w x y z=5 w x 41$ and we know that $w \neq 1$ and $x \neq 5,7$. To this point, this form is consistent with the 1st, 2 nd, 3 rd and 7 th rows of the table. Since $5 w x 41$ and 59135 have 1 matching digit, this is taken care of by the fact that $v=5$ and we note that $w \neq 9$ and $x \neq 1$. Since $5 w x 41$ and 58342 have 2 matching digits, this is taken care of by the fact that $v=5$ and $y=4$, and we note that $w \neq 8$ and $x \neq 3$. Since $5 w x 41$ and 37348 have 2 matching digits and $y=4$, then either $w=7$ or $x=3$. But we already know that $x \neq 3$, and so $w=7$. Therefore, vwxyz $=57 x 41$ with the restrictions that $x \neq 1,3,5,7$. We note that the integers $57041,57241,57441,57641,57841,57941$ satisfy the requirements, so are all possibilities for Sam's numbers. Case 2: vwxyz $=v w 54 z$ Since $v w 54 z$ and 51545 have only 2 matching digits, so $v \neq 5$ and $z \neq 5$. Since $v w 54 z$ and 21531 have 1 matching digit, then this is taken care of by the fact that $x=5$, and we note that $v \neq 2$ and $z \neq 1$. (We already know that $w \neq 1$.) Since $v w 54 z$ and 59135 have 1 matching digit, then $v=5$ or $w=9$ or $z=5$. This means that we must have $w=9$. Thus, vwxyz $=v 954 z$ and we know that $v \neq 2,7,5$ and $z \neq 1,4,5$. To this point, this form is consistent with the 1 st, 2 nd, 3 rd , 4 th, and 7 th rows of the table. Since $v 954 z$ and 58342 have 2 matching digits and $v \neq 5$, then $z=2$. Since $v 9542$ and 37348 have 2 matching digits, then $v=3$. In this case, the integer 39542 is the only possibility, and it satisfies all of the requirements. Case 3: vwxyz $=v w x 45$ Since $v w x 45$ and 21531 have 1 matching digit and we know that $w \neq 1$, then $v=2$ or $x=5$. But if $x=5$, then $v w 545$ and 51545 would have 3 matching digits, so $x \neq 5$ and $v=2$. Thus, vwxyz $=2 w x 45$ and we know that $w \neq 1$ and $x \neq 5,7$. To this point, this form is consistent with the 1st, 2 nd, 3rd and 7 th rows of the table. Since $2 w x 45$ and 59135 have 1 matching digit, this is taken care of by the fact that $z=5$ and we note that $w \neq 9$ and $x \neq 1$. Since $2 w x 45$ and 58342 have 2 matching digits, then $w=8$ or $x=3$, but not both. Since $2 w x 45$ and 37348 have 2 matching digits, then $w=7$ or $x=3$, but not both. If $w=8$, then we have to have $x \neq 3$, and so neither $w=7$ nor $x=3$ is true. Thus, it must be the case that $x=3$ and $w \neq 7,8$. Therefore, vwxyz $=2 w 345$ with the restrictions that $w \neq 1,7,8,9$. We note that the integers $20345,22345,23345,24345,25345,26345$ satisfy the requirements, so are all possibilities for Sam's numbers. Thus, there are 13 possibilities for Sam's numbers and the sum of these is 526758.
526758
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
What is the value of $m$ if Tobias downloads $m$ apps, each app costs $\$ 2.00$ plus $10 \%$ tax, and he spends $\$ 52.80$ in total on these $m$ apps?
Since the tax rate is $10 \%$, then the tax on each $\$ 2.00$ app is $\$ 2.00 \times \frac{10}{100}=\$ 0.20$. Therefore, including tax, each app costs $\$ 2.00+\$ 0.20=\$ 2.20$. Since Tobias spends $\$ 52.80$ on apps, he downloads $\frac{\$ 52.80}{\$ 2.20}=24$ apps. Therefore, $m=24$.
24
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
Pascal High School organized three different trips. Fifty percent of the students went on the first trip, $80 \%$ went on the second trip, and $90 \%$ went on the third trip. A total of 160 students went on all three trips, and all of the other students went on exactly two trips. How many students are at Pascal High School?
Let $x$ be the total number of students at Pascal H.S. Let $a$ be the total number of students who went on both the first trip and the second trip, but did not go on the third trip. Let $b$ be the total number of students who went on both the first trip and the third trip, but did not go on the second trip. Let $c$ be the total number of students who went on both the second trip and the third trip, but did not go on the first trip. We note that no student went on one trip only, and that 160 students went on all three trips. We draw a Venn diagram: Since the total number of students at the school is $x$ and each region in the diagram is labelled separately, then $x=a+b+c+160$. From the given information: - $50 \%$ of the students in the school went on the first trip, so $0.5x=a+b+160$ - $80 \%$ of the students in the school went on the second trip, so $0.8x=a+c+160$ - $90 \%$ of the students in the school went on the third trip, so $0.9x=b+c+160$ Combining all of this information, $2x=2a+2b+2c+160+160=0.5x+0.8x+(0.9x-160)=2.2x-160$. Solving for $x$, we find $x=800$. Therefore, there are 800 students at Pascal High School.
800
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Fractions" ]
1
If $\frac{1}{3}$ of $x$ is equal to 4, what is $\frac{1}{6}$ of $x$?
Since $\frac{1}{3}$ of $x$ is equal to 4, then $x$ is equal to $3 \times 4$ or 12. Thus, $\frac{1}{6}$ of $x$ is equal to $12 \div 6=2$. Alternatively, since $\frac{1}{6}$ is one-half of $\frac{1}{3}$, then $\frac{1}{6}$ of $x$ is equal to one-half of $\frac{1}{3}$ of $x$, which is $4 \div 2$ or 2.
2
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
A line with equation \( y = 2x + b \) passes through the point \((-4, 0)\). What is the value of \(b\)?
Since the line with equation \( y = 2x + b \) passes through the point \((-4, 0)\), the coordinates of the point must satisfy the equation of the line. Substituting \(x = -4\) and \(y = 0\) gives \(0 = 2(-4) + b\) and so \(0 = -8 + b\) which gives \(b = 8\).
8
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
How many odd integers are there between $ rac{17}{4}$ and $ rac{35}{2}$?
We note that $ rac{17}{4}=4 rac{1}{4}$ and $ rac{35}{2}=17 rac{1}{2}$. Therefore, the integers between these two numbers are the integers from 5 to 17, inclusive. The odd integers in this range are $5,7,9,11,13,15$, and 17, of which there are 7.
7
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
Evaluate the expression $2^{3}-2+3$.
Evaluating, $2^{3}-2+3=2 imes 2 imes 2-2+3=8-2+3=9$.
9
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Equations -> Other" ]
1.5
Natalie and Harpreet are the same height. Jiayin's height is 161 cm. The average (mean) of the heights of Natalie, Harpreet and Jiayin is 171 cm. What is Natalie's height?
Since the average of three heights is 171 cm, then the sum of these three heights is 3 \times 171 \mathrm{~cm} or 513 cm. Since Jiayin's height is 161 cm, then the sum of Natalie's and Harpreet's heights must equal 513 \mathrm{~cm} - 161 \mathrm{~cm} = 352 \mathrm{~cm}. Since Harpreet and Natalie are the same height, this height is \frac{352 \mathrm{~cm}}{2} = 176 \mathrm{~cm}. Therefore, Natalie's height is 176 cm.
176 \text{ cm}
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems", "Mathematics -> Applied Mathematics -> Statistics -> Probability -> Other" ]
1
How many students chose Greek food if 200 students were asked to choose between pizza, Thai food, or Greek food, and the circle graph shows the results?
Of the 200 students, $50 \%$ (or one-half) of the students chose Greek food. Since one-half of 200 is 100, then 100 students chose Greek food.
100
pascal
[ "Mathematics -> Applied Mathematics -> Statistics -> Probability -> Counting Methods -> Other" ]
1
A box contains 5 black ties, 7 gold ties, and 8 pink ties. What is the probability that Stephen randomly chooses a pink tie?
There are \(5+7+8=20\) ties in the box, 8 of which are pink. When Stephen removes a tie at random, the probability of choosing a pink tie is \(\frac{8}{20}\) which is equivalent to \(\frac{2}{5}\).
\frac{2}{5}
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
Calculate the value of the expression $2+3 imes 5+2$.
Calculating, $2+3 imes 5+2=2+15+2=19$.
19
fermat
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
If $2x-3=10$, what is the value of $4x$?
Since $2x-3=10$, then $2x=13$ and so $4x=2(2x)=2(13)=26$. (We did not have to determine the value of $x$.)
26
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
What is the value of $1^{3}+2^{3}+3^{3}+4^{3}$?
Expanding and simplifying, $1^{3}+2^{3}+3^{3}+4^{3}=1 \times 1 \times 1+2 \times 2 \times 2+3 \times 3 \times 3+4 \times 4 \times 4=1+8+27+64=100$. Since $100=10^{2}$, then $1^{3}+2^{3}+3^{3}+4^{3}=10^{2}$.
10^{2}
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Exponents -> Other" ]
1
If $4^{n}=64^{2}$, what is the value of $n$?
We note that $64=4 \times 4 \times 4$. Thus, $64^{2}=64 \times 64=4 \times 4 \times 4 \times 4 \times 4 \times 4$. Since $4^{n}=64^{2}$, then $4^{n}=4 \times 4 \times 4 \times 4 \times 4 \times 4$ and so $n=6$.
6
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
Natascha cycles 3 times as fast as she runs. She spends 4 hours cycling and 1 hour running. What is the ratio of the distance that she cycles to the distance that she runs?
Suppose that Natascha runs at $r \mathrm{~km} / \mathrm{h}$. Since she cycles 3 times as fast as she runs, she cycles at $3 r \mathrm{~km} / \mathrm{h}$. In 1 hour of running, Natascha runs $(1 \mathrm{~h}) \cdot(r \mathrm{~km} / \mathrm{h})=r \mathrm{~km}$. In 4 hours of cycling, Natascha cycles $(4 \mathrm{~h}) \cdot(3 r \mathrm{~km} / \mathrm{h})=12 r \mathrm{~km}$. Thus, the ratio of the distance that she cycles to the distance that she runs is equivalent to the ratio $12 r \mathrm{~km}: r \mathrm{~km}$ which is equivalent to $12: 1$.
12:1
fermat
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
A mass of 15 kg is halfway between 10 kg and 20 kg on the vertical axis. What is the age of the cod when its mass is 15 kg?
A mass of 15 kg is halfway between 10 kg and 20 kg on the vertical axis. The point where the graph reaches 15 kg is halfway between 6 and 8 on the horizontal axis. Therefore, the cod is 7 years old when its mass is 15 kg.
7
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1.5
Dewa writes down a list of four integers. He calculates the average of each group of three of the four integers. These averages are $32,39,40,44$. What is the largest of the four integers?
Suppose that Dewa's four numbers are $w, x, y, z$. The averages of the four possible groups of three of these are $\frac{w+x+y}{3}, \frac{w+x+z}{3}, \frac{w+y+z}{3}, \frac{x+y+z}{3}$. These averages are equal to $32,39,40,44$, in some order. The sums of the groups of three are equal to 3 times the averages, so are $96,117,120,132$, in some order. In other words, $w+x+y, w+x+z, w+y+z, x+y+z$ are equal to $96,117,120,132$ in some order. Therefore, $(w+x+y)+(w+x+z)+(w+y+z)+(x+y+z)=96+117+120+132$ and so $3 w+3 x+3 y+3 z=465$ which gives $w+x+y+z=155$. Since the sum of the four numbers is 155 and the sums of groups of 3 are $96,117,120,132$, then the four numbers are $155-96=59 \quad 155-117=38 \quad 155-120=35 \quad 155-132=23$ and so the largest number is 59.
59
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
If $4x + 14 = 8x - 48$, what is the value of $2x$?
Since $4x + 14 = 8x - 48$, then $14 + 48 = 8x - 4x$ or $62 = 4x$. Dividing both sides of this equation by 2, we obtain $\frac{4x}{2} = \frac{62}{2}$ which gives $2x = 31$.
31
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
The average age of Andras, Frances, and Gerta is 22 years. Given that Andras is 23 and Frances is 24, what is Gerta's age?
Since the average of the three ages is 22, the sum of the three ages is \( 3 \times 22 = 66 \). Since Andras' age is 23 and Frances' age is 24, then Gerta's age is \( 66 - 23 - 24 = 19 \).
19
pascal
[ "Mathematics -> Geometry -> Solid Geometry -> Volume" ]
1.5
A rectangular prism has a volume of $12 \mathrm{~cm}^{3}$. A new prism is formed by doubling the length, doubling the width, and tripling the height of the original prism. What is the volume of this new prism?
Suppose that the original prism has length $\ell \mathrm{cm}$, width $w \mathrm{~cm}$, and height $h \mathrm{~cm}$. Since the volume of this prism is $12 \mathrm{~cm}^{3}$, then $\ell w h=12$. The new prism has length $2 \ell \mathrm{cm}$, width $2 w \mathrm{~cm}$, and height 3 cm. The volume of this prism, in $\mathrm{cm}^{3}$, is $(2 l) \times(2 w) \times(3 h)=2 \times 2 \times 3 \times l w h=12 \times 12=144$.
144
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Fractions" ]
1
What is the value of the expression $ rac{3}{10}+ rac{3}{100}+ rac{3}{1000}$?
Evaluating, $ rac{3}{10}+ rac{3}{100}+ rac{3}{1000}=0.3+0.03+0.003=0.333$.
0.333
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1.5
Three integers from the list $1,2,4,8,16,20$ have a product of 80. What is the sum of these three integers?
The three integers from the list whose product is 80 are 1, 4, and 20, since $1 \times 4 \times 20=80$. The sum of these integers is $1+4+20=25$. (Since 80 is a multiple of 5 and 20 is the only integer in the list that is a multiple of 5, then 20 must be included in the product. This leaves two integers to choose, and their product must be $\frac{80}{20}=4$. From the given list, these integers must be 1 and 4.)
25
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
Krystyna has some raisins. After giving some away and eating some, she has 16 left. How many did she start with?
Working backwards, Krystyna had 36 raisins before eating 4, and 54 raisins initially.
54
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
Hagrid has 100 animals. Among these animals, each is either striped or spotted but not both, each has either wings or horns but not both, there are 28 striped animals with wings, there are 62 spotted animals, and there are 36 animals with horns. How many of Hagrid's spotted animals have horns?
Each of the animals is either striped or spotted, but not both. Since there are 100 animals and 62 are spotted, then there are $100 - 62 = 38$ striped animals. Each striped animal must have wings or a horn, but not both. Since there are 28 striped animals with wings, then there are $38 - 28 = 10$ striped animals with horns. Each animal with a horn must be either striped or spotted. Since there are 36 animals with horns, then there are $36 - 10 = 26$ spotted animals with horns.
26
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Fractions" ]
1.5
What is \( 110\% \) of 500?
Solution 1: \( 10\% \) of 500 is \( \frac{1}{10} \) or 0.1 of 500, which equals 50. \( 100\% \) of 500 is 500. Thus, \( 110\% \) of 500 equals \( 500 + 50 \), which equals 550. Solution 2: \( 110\% \) of 500 is equal to \( \frac{110}{100} \times 500 = 110 \times 5 = 550 \).
550
cayley
[ "Mathematics -> Algebra -> Prealgebra -> Decimals" ]
1
What is the difference between the largest and smallest numbers in the list $0.023,0.302,0.203,0.320,0.032$?
We write the list in increasing order: $0.023,0.032,0.203,0.302,0.320$. The difference between the largest and smallest of these numbers is $0.320-0.023=0.297$.
0.297
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Fractions" ]
1.5
Calculate the value of $\sqrt{\frac{\sqrt{81} + \sqrt{81}}{2}}$.
Calculating, $\sqrt{\frac{\sqrt{81} + \sqrt{81}}{2}} = \sqrt{\frac{9 + 9}{2}} = \sqrt{9} = 3$.
3
fermat
[ "Mathematics -> Algebra -> Prealgebra -> Fractions" ]
1.5
A group of friends are sharing a bag of candy. On the first day, they eat $ rac{1}{2}$ of the candies in the bag. On the second day, they eat $ rac{2}{3}$ of the remaining candies. On the third day, they eat $ rac{3}{4}$ of the remaining candies. On the fourth day, they eat $ rac{4}{5}$ of the remaining candies. On the fifth day, they eat $ rac{5}{6}$ of the remaining candies. At the end of the fifth day, there is 1 candy remaining in the bag. How many candies were in the bag before the first day?
We work backwards through the given information. At the end, there is 1 candy remaining. Since $ rac{5}{6}$ of the candies are removed on the fifth day, this 1 candy represents $ rac{1}{6}$ of the candies left at the end of the fourth day. Thus, there were $6 imes 1=6$ candies left at the end of the fourth day. Since $ rac{4}{5}$ of the candies are removed on the fourth day, these 6 candies represent $ rac{1}{5}$ of the candies left at the end of the third day. Thus, there were $5 imes 6=30$ candies left at the end of the third day. Since $ rac{3}{4}$ of the candies are removed on the third day, these 30 candies represent $ rac{1}{4}$ of the candies left at the end of the second day. Thus, there were $4 imes 30=120$ candies left at the end of the second day. Since $ rac{2}{3}$ of the candies are removed on the second day, these 120 candies represent $ rac{1}{3}$ of the candies left at the end of the first day. Thus, there were $3 imes 120=360$ candies left at the end of the first day. Since $ rac{1}{2}$ of the candies are removed on the first day, these 360 candies represent $ rac{1}{2}$ of the candies initially in the bag. Thus, there were $2 imes 360=720$ in the bag at the beginning.
720
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
Wesley is a professional runner. He ran five laps around a track. His times for the five laps were 63 seconds, 1 minute, 1.5 minutes, 68 seconds, and 57 seconds. What is the median of these times?
Since there are 60 seconds in 1 minute, the number of seconds in 1.5 minutes is $1.5 imes 60=90$. Thus, Wesley's times were 63 seconds, 60 seconds, 90 seconds, 68 seconds, and 57 seconds. When these times in seconds are arranged in increasing order, we obtain $57,60,63,68,90$. Thus, the median time is 63 seconds.
63 ext{ seconds}
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
If $x=11$, $y=-8$, and $2x-3z=5y$, what is the value of $z$?
Since $x=11$, $y=-8$ and $2x-3z=5y$, then $2 \times 11-3z=5 \times(-8)$ or $22-3z=-40$. Therefore, $3z=22+40=62$ and so $z=\frac{62}{3}$.
\frac{62}{3}
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1.5
In the subtraction shown, $K, L, M$, and $N$ are digits. What is the value of $K+L+M+N$?\n$$\begin{array}{r}6 K 0 L \\ -\quad M 9 N 4 \\ \hline 2011\end{array}$$
We work from right to left as we would if doing this calculation by hand. In the units column, we have $L-4$ giving 1. Thus, $L=5$. (There is no borrowing required.) In the tens column, we have $0-N$ giving 1. Since 1 is larger than 0, we must borrow from the hundreds column. Thus, $10-N$ gives 1, which means $N=9$. In the hundreds column, we have $K-9$ but we have already borrowed 1 from $K$, so we have $(K-1)-9$ giving 0. Therefore, we must be subtracting 9 from 9, which means that $K$ should be 10, which is not possible. We can conclude, though, that $K=0$ and that we have borrowed from the 6. In the thousands column, we have $5-M=2$ or $M=3$. This gives $6005-3994=2011$, which is correct. Finally, $K+L+M+N=0+5+3+9=17$.
17
pascal
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
The time on a cell phone is $3:52$. How many minutes will pass before the phone next shows a time using each of the digits 2, 3, and 5 exactly once?
There are six times that can be made using each of the digits 2, 3, and 5 exactly once: $2:35$, $2:53$, $3:25$, $3:52$, $5:23$, and $5:32$. The first of these that occurs after 3:52 is 5:23. From 3:52 to $4:00$, 8 minutes pass. From 4:00 to 5:00, 60 minutes pass. From 5:00 to 5:23, 23 minutes pass. Therefore, from $3:52$ to $5:23$, which is the next time that uses the digits 2, 3, and 5 each exactly once, a total of $8+60+23=91$ minutes pass.
91
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
Jing purchased eight identical items. If the total cost was $\$ 26$, what is the cost per item, in dollars?
Since Jing purchased 8 identical items and the total cost was $\$ 26$, then to obtain the cost per item, she divides the total cost by the number of items. Thus, the answer is $26 \div 8$.
\frac{26}{8}
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Fractions" ]
1.5
Suppose that $\sqrt{\frac{1}{2} \times \frac{2}{3} \times \frac{3}{4} \times \frac{4}{5} \times \cdots \times \frac{n-1}{n}} = \frac{1}{8}$. What is the value of $n$?
Since $\sqrt{\frac{1}{2} \times \frac{2}{3} \times \frac{3}{4} \times \frac{4}{5} \times \cdots \times \frac{n-1}{n}} = \frac{1}{8}$, then squaring both sides, we obtain $\frac{1}{2} \times \frac{2}{3} \times \frac{3}{4} \times \frac{4}{5} \times \cdots \times \frac{n-1}{n} = \frac{1}{64}$. Simplifying the left side, we obtain $\frac{1 \times 2 \times 3 \times 4 \times \cdots \times (n-1)}{2 \times 3 \times 4 \times 5 \times \cdots \times n} = \frac{1}{64}$ or $\frac{1 \times (2 \times 3 \times 4 \times \cdots \times (n-1))}{(2 \times 3 \times 4 \times \cdots \times (n-1)) \times n} = \frac{1}{64}$ and so $\frac{1}{n} = \frac{1}{64}$ which means that $n = 64$.
64
cayley
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1.5
Nasim buys trading cards in packages of 5 cards and in packages of 8 cards. He can purchase exactly 18 cards by buying two 5-packs and one 8-pack, but he cannot purchase exactly 12 cards with any combination of packages. For how many of the integers $n=24,25,26,27,28,29$ can he buy exactly $n$ cards?
Nasim can buy 24 cards by buying three 8-packs $(3 imes 8=24)$. Nasim can buy 25 cards by buying five 5-packs $(5 imes 5=25)$. Nasim can buy 26 cards by buying two 5-packs and two 8-packs $(2 imes 5+2 imes 8=26)$. Nasim can buy 28 cards by buying four 5-packs and one 8-pack $(4 imes 5+1 imes 8=28)$. Nasim can buy 29 cards by buying one 5-pack and three 8-packs $(1 imes 5+3 imes 8=29)$. Nasim cannot buy exactly 27 cards, because the number of cards in 8-packs that he buys would be $0,8,16$, or 24, leaving $27,19,11$, or 3 cards to buy in 5-packs. None of these are possible, since none of $27,19,11$, or 3 is a multiple of 5. Therefore, for 5 of the 6 values of $n$, Nasim can buy exactly $n$ cards.
5
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
Robyn has 4 tasks to do and Sasha has 14 tasks to do. How many of Sasha's tasks should Robyn do in order for them to have the same number of tasks?
Between them, Robyn and Sasha have \(4 + 14 = 18\) tasks to do. If each does the same number of tasks, each must do \(18 \div 2 = 9\) tasks. This means that Robyn must do \(9 - 4 = 5\) of Sasha's tasks.
5
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers", "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
Yann writes down the first $n$ consecutive positive integers, $1,2,3,4, \ldots, n-1, n$. He removes four different integers $p, q, r, s$ from the list. At least three of $p, q, r, s$ are consecutive and $100<p<q<r<s$. The average of the integers remaining in the list is 89.5625. What is the number of possible values of $s$?
When Yann removes 4 of the $n$ integers from his list, there are $n-4$ integers left. Suppose that the sum of the $n-4$ integers left is $T$. The average of these $n-4$ integers is $89.5625=89.5+0.0625=89+\frac{1}{2}+\frac{1}{16}=89 \frac{9}{16}=\frac{1433}{16}$. Since the sum of the $n-4$ integers is $T$, then $\frac{T}{n-4}=\frac{1433}{16}$ which means that $16 T=1433(n-4)$. Since 1433 and 16 have no common divisor larger than 1 (the positive divisors of 16 are 1, 2, 4, 8, 16, none of which other than 1 is a divisor of 1433), the value of $n-4$ is a multiple of 16. Since $100<p<q<r<s$, the original list includes more than 100 numbers. Since the original list includes consecutive integers starting at 1 and only 4 of more than 100 numbers are removed, it seems likely that the average of the original list and the average of the new list should be relatively similar. Since the average of the new list is 89.5625 which is close to 90, it seems reasonable to say that the average of the original list is close to 90. Since the original list is a list of consecutive positive integers starting at 1, this means that we would guess that the original list has roughly 180 integers in it. In other words, $n$ appears to be near 180. We do know that $n-4$ is a multiple of 16. The closest multiples of 16 to 180 are 160, 176 and 192, which correspond to $n=164, n=180$, and $n=196$. Suppose that $n=180$, which seems like the most likely possibility. We will show at the end of the solution that this is the only possible value of $n$. The equation $\frac{T}{n-4}=89.5625$ gives $T=176 \times 89.5625=15763$. The sum of the $n$ integers in the original list is $1+2+3+4+\cdots+(n-1)+n=\frac{1}{2} n(n+1)$. When $n=180$, the sum of the integers $1,2,3, \ldots, 178,179,180$ is $\frac{1}{2}(180)(181)=16290$. Since the sum of the numbers in the original list is 16290 and the sum once the four numbers are removed is 15763, the sum of the four numbers removed is $16290-15763=527$. In other words, $p+q+r+s=527$. We now want to count the number of ways in which we can choose $p, q, r, s$ with the conditions that $100<p<q<r<s \leq 180$ and $p+q+r+s=527$ with at least three of $p, q, r, s$ consecutive. The fourth of these integers is at least 101 and at most 180, which means that the sum of the three consecutive integers is at least $527-180=347$ and is at most $527-101=426$. This means that the consecutive integers are at least $115,116,117$ (whose sum is 348) since $114+115+116=345$ which is too small and smaller integers will give sums that are smaller still. If $p, q, r$ equal $115,116,117$, then $s=527-348=179$. The consecutive integers are at most $141,142,143$ (whose sum is 426) since $142+143+144=429$ which is too large and larger integers will give sums that are larger still. If $p, q, r$ equal $141,142,143$, then $s=527-426=101$. When each of the three consecutive integers is increased by 1 and the sum is constant, the fourth integer is decreased by 3 to maintain this constant sum. Using all of this, we obtain the following lists $p, q, r, s$: $115,116,117,179$; $116,117, 118, 176$; ... ; $130,131, 132, 134$ $128,132,133,134$; $125,133,134,135$; ... ; $101,141,142,143$ Note that we cannot use 131, 132, 133, 131, since $p, q, r, s$ must be distinct. There are 26 lists of integers that can be removed (16 in the first set and 10 in the second set). The corresponding values of $s$ are: $179,176,173,170,167,164,161,158,155,152,149,146,143,140,137,134$ $134,135,136,137,138,139,140,141,142,143$ There are 4 values of $s$ that overlap between the two lists, and so there are $26-4=22$ possible values for $s$. Why is $n=180$ the only possible value of $n$? To see this, we use the fact that the average of the list of consecutive integers starting at $a$ and ending at $b$ equals the average of $a$ and $b$, or $\frac{a+b}{2}$. (This is true because the integers in the list have a constant difference and are thus evenly distributed, which means that the average of the first and last integers will equal the average of all of the integers in the list.) The original list of integers is $1,2, \ldots, n-1, n$ which has an average of $\frac{n+1}{2}$. If the four largest integers are removed from the list, the new list is $1,2, \ldots, n-5, n-4$, which has an average of $\frac{n-3}{2}$. If the four smallest integers are removed from the list, the new list is $5,6, \ldots, n-1, n$, which has an average of $\frac{n+5}{2}$. When any four integers are removed, the sum of the remaining integers is greater than or equal to the sum of $1,2, \ldots, n-5, n-4$ and less than or equal to the sum of $5,6, \ldots, n-1, n$. Since the denominator in the average calculation remains the same, the average of any of the lists after four numbers are removed is at least $\frac{n-3}{2}$ and at most $\frac{n+5}{2}$. This means that the actual average (which is 89.5625) is greater than or equal to $\frac{n-3}{2}$ and less than or equal to $\frac{n+5}{2}$. Since $89.5625 \geq \frac{n-3}{2}$, then $n-3 \leq 179.125$ and so $n \leq 182.125$. Since $89.5625 \leq \frac{n+5}{2}$, then $n+5 \geq 179.125$ and so $n \geq 174.125$. Since $n$ is an integer, then $175 \leq n \leq 182$ and so $171 \leq n-4 \leq 178$. Since $n-4$ is a multiple of 16, then $n-4=176$ and so $n=180$, as required.
22
pascal
[ "Mathematics -> Applied Mathematics -> Statistics -> Probability -> Counting Methods -> Combinations", "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
Alvin, Bingyi, and Cheska play a two-player game that never ends in a tie. In a recent tournament between the three players, a total of 60 games were played and each pair of players played the same number of games. When Alvin and Bingyi played, Alvin won \(20\%\) of the games. When Bingyi and Cheska played, Bingyi won \(60\%\) of the games. When Cheska and Alvin played, Cheska won \(40\%\) of the games. How many games did Bingyi win?
Since 60 games are played and each of the 3 pairs plays the same number of games, each pair plays \(60 \div 3 = 20\) games. Alvin wins \(20\%\) of the 20 games that Alvin and Bingyi play, so Alvin wins \(\frac{20}{100} \times 20 = \frac{1}{5} \times 20 = 4\) of these 20 games and Bingyi wins \(20 - 4 = 16\) of these 20 games. Bingyi wins \(60\%\) of the 20 games that Bingyi and Cheska play, so Bingyi wins a total of \(\frac{60}{100} \times 20 = \frac{3}{5} \times 20 = 12\) of these 20 games. The games played by Cheska and Alvin do not affect Bingyi's total number of wins. In total, Bingyi wins \(16 + 12 = 28\) games.
28
pascal
[ "Mathematics -> Geometry -> Plane Geometry -> Polygons" ]
1.5
A sequence of figures is formed using tiles. Each tile is an equilateral triangle with side length 7 cm. The first figure consists of 1 tile. Each figure after the first is formed by adding 1 tile to the previous figure. How many tiles are used to form the figure in the sequence with perimeter 91 cm?
The first figure consists of one tile with perimeter $3 \times 7 \mathrm{~cm} = 21 \mathrm{~cm}$. Each time an additional tile is added, the perimeter of the figure increases by 7 cm (one side length of a tile), because one side length of the previous figure is 'covered up' and two new side lengths of a tile are added to the perimeter for a net increase of one side length (or 7 cm). Since the first figure has perimeter 21 cm and we are looking for the figure with perimeter 91 cm, then the perimeter must increase by $91 \mathrm{~cm} - 21 \mathrm{~cm} = 70 \mathrm{~cm}$. Since the perimeter increases by 7 cm when each tile is added, then $\frac{70 \mathrm{~cm}}{7 \mathrm{~cm} / \mathrm{tile}} = 10$ tiles need to be added to reach a perimeter of 91 cm. In total, this figure will have $1 + 10 = 11$ tiles.
11
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Fractions" ]
1
On the number line, points $M$ and $N$ divide $L P$ into three equal parts. What is the value at $M$?
The difference between $\frac{1}{6}$ and $\frac{1}{12}$ is $\frac{1}{6}-\frac{1}{12}=\frac{2}{12}-\frac{1}{12}=\frac{1}{12}$, so $L P=\frac{1}{12}$. Since $L P$ is divided into three equal parts, then this distance is divided into three equal parts, each equal to $\frac{1}{12} \div 3=\frac{1}{12} \times \frac{1}{3}=\frac{1}{36}$. Therefore, $M$ is located $\frac{1}{36}$ to the right of $L$. Thus, the value at $M$ is $\frac{1}{12}+\frac{1}{36}=\frac{3}{36}+\frac{1}{36}=\frac{4}{36}=\frac{1}{9}$.
\frac{1}{9}
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
The operation $\nabla$ is defined by $a \nabla b=4 a+b$. What is the value of $(5 \nabla 2) \nabla 2$?
Using the definition, $(5 \nabla 2) \nabla 2=(4 \times 5+2) \nabla 2=22 \nabla 2=4 \times 22+2=90$.
90
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
The operation $\nabla$ is defined by $g \nabla h=g^{2}-h^{2}$. If $g>0$ and $g \nabla 6=45$, what is the value of $g$?
Using the definition of the operation, $g \nabla 6=45$ gives $g^{2}-6^{2}=45$. Thus, $g^{2}=45+36=81$. Since $g>0$, then $g=\sqrt{81}=9$.
9
pascal
[ "Mathematics -> Applied Mathematics -> Statistics -> Probability -> Other" ]
1.5
Ellie's drawer of hair clips contains 4 red clips, 5 blue clips, and 7 green clips. Each morning, she randomly chooses one hair clip to wear for the day. She returns this clip to the drawer each evening. One morning, Kyne removes $k$ hair clips before Ellie can make her daily selection. As a result, the probability that Ellie chooses a red clip is doubled. What is a possible value of $k$?
Before Kyne removes hair clips, Ellie has 4 red clips and $4+5+7=16$ clips in total, so the probability that she randomly chooses a red clip is $ rac{4}{16}$ which equals $ rac{1}{4}$. After Kyne removes the clips, the probability that Ellie chooses a red clip is $2 imes rac{1}{4}$ or $ rac{1}{2}$. Since Ellie starts with 4 red clips, then after Kyne removes some clips, Ellie must have 4, 3, 2, 1, or 0 red clips. Since the probability that Ellie chooses a red clip is larger than 0, she cannot have 0 red clips. Since the probability of her choosing a red clip is $ rac{1}{2}$, then the total number of clips that she has after $k$ are removed must be twice the number of red clips, so could be $8,6,4$, or 2. Thus, the possible values of $k$ are $16-8=8$ or $16-6=10$ or $16-4=12$ or $16-2=14$. Of these, 12 is one of the given possibilities.
12
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
What is the sum of the first 9 positive multiples of 5?
Since $1+2+3+4+5+6+7+8+9=45$ then $5+10+15+\cdots+40+45=5(1+2+3+\cdots+8+9)=5(45)=225$
225
cayley
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
If $(2)(3)(4) = 6x$, what is the value of $x$?
Since $(2)(3)(4) = 6x$, then $6(4) = 6x$. Dividing both sides by 6, we obtain $x = 4$.
4
cayley
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1
Narsa buys a package of 45 cookies on Monday morning. How many cookies are left in the package after Friday?
On Monday, Narsa ate 4 cookies. On Tuesday, Narsa ate 12 cookies. On Wednesday, Narsa ate 8 cookies. On Thursday, Narsa ate 0 cookies. On Friday, Narsa ate 6 cookies. This means that Narsa ate $4+12+8+0+6=30$ cookies. Since the package started with 45 cookies, there are $45-30=15$ cookies left in the package after Friday.
15
pascal
[ "Mathematics -> Geometry -> Plane Geometry -> Area" ]
1.5
What is the side length of the larger square if a small square is drawn inside a larger square, and the area of the shaded region and the area of the unshaded region are each $18 \mathrm{~cm}^{2}$?
Since the area of the larger square equals the sum of the areas of the shaded and unshaded regions inside, then the area of the larger square equals $2 \times 18 \mathrm{~cm}^{2}=36 \mathrm{~cm}^{2}$. Since the larger square has an area of $36 \mathrm{~cm}^{2}$, then its side length is $\sqrt{36 \mathrm{~cm}^{2}}=6 \mathrm{~cm}$.
6 \mathrm{~cm}
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Equations -> Other" ]
1
If $m+1= rac{n-2}{3}$, what is the value of $3 m-n$?
Since $m+1= rac{n-2}{3}$, then $3(m+1)=n-2$. This means that $3 m+3=n-2$ and so $3 m-n=-2-3=-5$.
-5
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
A numerical value is assigned to each letter of the alphabet. The value of a word is determined by adding up the numerical values of each of its letters. The value of SET is 2, the value of HAT is 7, the value of TASTE is 3, and the value of MAT is 4. What is the value of the word MATH?
From the given information, we know that $S+E+T=2$, $H+A+T=7$, $T+A+S+T+E=3$, and $M+A+T=4$. Since $T+A+S+T+E=3$ and $S+E+T=2$, then $T+A=3-2=1$. Since $H+A+T=7$ and $T+A=1$, then $H=7-1=6$. Since $M+A+T=4$ and $H=7$, then $M+(A+T)+H=4+6=10$. Therefore, the value of the word MATH is 10.
10
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
When $x=3$ and $y=4$, what is the value of the expression $xy-x$?
When $x=3$ and $y=4$, we get $xy-x=3 \times 4-3=12-3=9$. Alternatively, $xy-x=x(y-1)=3 \times 3=9$.
9
cayley
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
When 542 is multiplied by 3, what is the ones (units) digit of the result?
Since \( 542 \times 3 = 1626 \), the ones digit of the result is 6.
6
cayley
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
Many of the students in M. Gamache's class brought a skateboard or a bicycle to school yesterday. The ratio of the number of skateboards to the number of bicycles was $7:4$. There were 12 more skateboards than bicycles. How many skateboards and bicycles were there in total?
Since the ratio of the number of skateboards to the number of bicycles was $7:4$, then the numbers of skateboards and bicycles can be written in the form $7k$ and $4k$ for some positive integer $k$. Since the difference between the numbers of skateboards and bicycles is 12, then $7k - 4k = 12$ and so $3k = 12$ or $k = 4$. Therefore, the total number of skateboards and bicycles is $7k + 4k = 11k = 11 \times 4 = 44$.
44
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
If \( x = 2 \) and \( y = x^2 - 5 \) and \( z = y^2 - 5 \), what is the value of \( z \)?
Since \( x = 2 \) and \( y = x^2 - 5 \), then \( y = 2^2 - 5 = 4 - 5 = -1 \). Since \( y = -1 \) and \( z = y^2 - 5 \), then \( z = (-1)^2 - 5 = 1 - 5 = -4 \).
-4
cayley
[ "Mathematics -> Geometry -> Plane Geometry -> Polygons" ]
1.5
Six rhombi of side length 1 are arranged as shown. What is the perimeter of this figure?
The first rhombus and the last rhombus each have three edges that form part of the exterior of the figure, and so they each contribute 3 to the perimeter. The inner four rhombi each have two edges that form part of the exterior of the figure, and so they each contribute 2 to the perimeter. Thus, the perimeter is $2 \times 3+4 \times 2=14$.
14
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Fractions" ]
1.5
When $x=2021$, what is the value of $ rac{4x}{x+2x}$?
When $x eq 0$, we obtain $ rac{4 x}{x+2 x}= rac{4 x}{3 x}= rac{4}{3}$. Thus, when $x=2021$, we have $ rac{4 x}{x+2 x}= rac{8084}{2021+4042}= rac{8084}{6063}= rac{4}{3}$.
rac{4}{3}
fermat
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
If $2n + 5 = 16$, what is the value of the expression $2n - 3$?
Since $2n + 5 = 16$, then $2n - 3 = (2n + 5) - 8 = 16 - 8 = 8$. Alternatively, we could solve the equation $2n + 5 = 16$ to obtain $2n = 11$ or $n = \frac{11}{2}$. From this, we see that $2n - 3 = 2\left(\frac{11}{2}\right) - 3 = 11 - 3 = 8$.
8
cayley
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
Last summer, Pat worked at a summer camp. For each day that he worked, he earned \$100 and he was not charged for food. For each day that he did not work, he was not paid and he was charged \$20 for food. After 70 days, the money that he earned minus his food costs equalled \$5440. On how many of these 70 days did Pat work?
Let \( x \) be the number of days on which Pat worked. On each of these days, he earned \$100 and had no food costs, so he earned a total of \( 100x \) dollars. Since Pat worked for \( x \) of the 70 days, then he did not work on \( 70-x \) days. On each of these days, he earned no money and was charged \$20 for food, so was charged a total of \( 20(70-x) \) dollars for food. After 70 days, the money that he earned minus his food costs equalled \$5440. Algebraically, we get \( 100x-20(70-x)=5440 \). Thus, \( 100x-1400+20x=5440 \) or \( 120x=6840 \), which gives \( x=57 \). Therefore, Pat worked on 57 of these 70 days.
57
fermat
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
If $3+\triangle=5$ and $\triangle+\square=7$, what is the value of $\triangle+\Delta+\Delta+\square+\square$?
Since $3+\triangle=5$, then $\triangle=5-3=2$. Since $\triangle+\square=7$ and $\triangle=2$, then $\square=5$. Thus, $\triangle+\Delta+\Delta+\square+\square=3 \times 2+2 \times 5=6+10=16$.
16
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1
If \( 3x + 4 = x + 2 \), what is the value of \( x \)?
If \( 3x + 4 = x + 2 \), then \( 3x - x = 2 - 4 \) and so \( 2x = -2 \), which gives \( x = -1 \).
-1
cayley
[ "Mathematics -> Applied Mathematics -> Statistics -> Probability -> Counting Methods -> Combinations" ]
1.5
Five students play chess matches against each other. Each student plays three matches against each of the other students. How many matches are played in total?
We label the players as A, B, C, D, and E. The total number of matches played will be equal to the number of pairs of players that can be formed times the number of matches that each pair plays. The possible pairs of players are AB, AC, AD, AE, BC, BD, BE, CD, CE, and DE. There are 10 such pairs. Thus, the total number of matches played is $10 imes 3=30$.
30
cayley
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
When three positive integers are added in pairs, the resulting sums are 998, 1050, and 1234. What is the difference between the largest and smallest of the three original positive integers?
Suppose that the three integers are $x, y$ and $z$ where $x+y=998$, $x+z=1050$, and $y+z=1234$. From the first two equations, $(x+z)-(x+y)=1050-998$ or $z-y=52$. Since $z+y=1234$ and $z-y=52$, then $(z+y)+(z-y)=1234+52$ or $2z=1286$ and so $z=643$. Since $z=643$ and $z-y=52$, then $y=z-52=643-52=591$. Since $x+y=998$ and $y=591$, then $x=998-y=998-591=407$. The three original numbers are 407, 591, and 643. The difference between the largest and smallest of these integers is $643-407=236$.
236
cayley
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
If the line that passes through the points $(2,7)$ and $(a, 3a)$ has a slope of 2, what is the value of $a$?
Since the slope of the line through points $(2,7)$ and $(a, 3a)$ is 2, then $ rac{3a-7}{a-2}=2$. From this, $3a-7=2(a-2)$ and so $3a-7=2a-4$ which gives $a=3$.
3
cayley
[ "Mathematics -> Geometry -> Solid Geometry -> Surface Area" ]
1
Three $1 imes 1 imes 1$ cubes are joined side by side. What is the surface area of the resulting prism?
When three $1 imes 1 imes 1$ cubes are joined together as in the diagram, the resulting prism is $3 imes 1 imes 1$. This prism has four rectangular faces that are $3 imes 1$ and two rectangular faces that are $1 imes 1$. Therefore, the surface area is $4 imes(3 imes 1)+2 imes(1 imes 1)=4 imes 3+2 imes 1=12+2=14$.
14
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
If a bag contains only green, yellow, and red marbles in the ratio $3: 4: 2$ and 63 of the marbles are not red, how many red marbles are in the bag?
Since the ratio of green marbles to yellow marbles to red marbles is $3: 4: 2$, then we can let the numbers of green, yellow and red marbles be $3n, 4n$ and $2n$ for some positive integer $n$. Since 63 of the marbles in the bag are not red, then $3n+4n=63$ and so $7n=63$ or $n=9$, which means that the number of red marbles in the bag is $2n=2 \times 9=18$.
18
cayley
[ "Mathematics -> Applied Mathematics -> Math Word Problems" ]
1.5
The Athenas are playing a 44 game season. They have 20 wins and 15 losses so far. What is the smallest number of their remaining games that they must win to make the playoffs, given they must win at least 60% of all of their games?
In order to make the playoffs, the Athenas must win at least 60% of their 44 games. That is, they must win at least $0.6 \times 44=26.4$ games. Since they must win an integer number of games, then the smallest number of games that they can win to make the playoffs is the smallest integer larger than 26.4, or 27. Since they have won 20 games so far, then they must win $27-20=7$ of their remaining games to make the playoffs.
7
cayley
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
If the number of zeros in the integer equal to $(10^{100}) imes (100^{10})$ is sought, what is this number?
Since $100=10^{2}$, then $100^{10}=(10^{2})^{10}=10^{20}$. Therefore, $(10^{100}) imes (100^{10})=(10^{100}) imes (10^{20})=10^{120}$. When written out, this integer consists of a 1 followed by 120 zeros.
120
cayley
[ "Mathematics -> Algebra -> Prealgebra -> Simple Equations" ]
1.5
If $4x + 14 = 8x - 48$, what is the value of $2x$?
Since $4x + 14 = 8x - 48$, then $14 + 48 = 8x - 4x$ or $62 = 4x$. Dividing both sides of this equation by 2, we obtain $\frac{4x}{2} = \frac{62}{2}$ which gives $2x = 31$.
31
pascal
[ "Mathematics -> Algebra -> Prealgebra -> Integers" ]
1
The integers -5 and 6 are shown on a number line. What is the distance between them?
The distance between two numbers on the number line is equal to their positive difference. Here, this distance is $6-(-5)=11$.
11
pascal