Reasoning and answer: Boris donates 24 / 4 = 6 books. Then Boris has a total of 24 - 6 = 18 books. Cameron donates 30 / 3 = 10 books. Then Cameron has a total of 30 - 10 = 20 books. Altogether, Boris and Cameron have 18 + 20 = 38 books.
The answer: 38
What was the question?
Question: Boris has 24 books and he donates a fourth of his books to the library. Cameron has 30 books and he donates a third of his books to the library. After donating their books, how many books in total do Boris and Cameron have together?


The total ratio for the cups of sugar and water needed to make lemonade is 1 + 2 = 3. In the 3 cups needed to make one liter of lemonade, the fraction representing the cups of sugar needed is 1 / 3. If she used 84 cups while making lemonade, she used 1 / 3 * 84 = 28 cups of sugar.
The answer: 28
Reverse engineering the question: Kara mixes cups of sugar and water in the ratio of 1:2 to make one liter of lemonade. Calculate the total number of cups of sugar used if she used 84 cups to make lemonade.


Reasoning and answer: 28 x 2 / 7 = 8 students were absent last Monday. So, 28 - 8 = 20 students were present last Monday.
The answer: 20
What was the question?
Question: There are 28 students in a class. Two-sevenths of them were absent last Monday. How many students were present last Monday?


Annie starts with 21 + 36 = 57 crayons. Bobby ends up giving her 36 / 2 = 18 crayons. Annie now has a total of 57 + 18 = 75 crayons. She ends up giving Mary a total of 75 * (1 / 3) = 25 crayons.
The answer: 25
Reverse engineering the question: Annie was given a pack of crayons. The pack contained 21 crayons. She already had a box of 36 crayons in her locker. Her friend Bobby gave her half the amount she already had in her locker. She decided to give her sister Mary 1/3 of her total amount of crayons. How many crayons does she give to Mary?


Reasoning and answer: In her 2 albums, Beyonce releases 2 * 15 = 30 songs. In her next album, Beyonce releases 1 * 20 = 20 songs. Since each single is one song, Beyonce releases a total of 30 + 20 + 5 = 55 songs.
The answer: 55
What was the question?
Question: Beyonce releases 5 different singles on iTunes. Then she releases 2 albums that each has 15 songs and 1 album that has 20 songs. How many songs has Beyonce released in total?


Reasoning and answer: First find the total number of miles Mark walks to get his lunch by multiplying the distance he walks back to the house by 2: 3 miles * 2 = 6 miles. Then find the total distance Mark walks by adding that distance to the distance between the house and the school: 6 miles + 9 miles = 15 miles. Now divide the total distance Mark walks by his speed to find how many hours he spends walking: 15 miles / 3 miles / hour = 5 hours. Now divide the total distance Chris walks by her speed to find the total time she spends walking: 9 miles / 3 miles / hour = 3 hours. Now subtract the time Chris spends walking from the time Mark spends walking to find the difference: 5 hours - 3 hours = 2.
The answer: 2
What was the question?
Question:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
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Mark and his sister Chris both leave their house for school at the same time. Mark travels at the same speed as Chris, who walks 3 miles per hour. After walking 3 miles Mark has to turn around and go home because he forgot his lunch. If the distance from their house to the school is 9 miles, how much longer does Mark spend walking than Chris?