Reasoning and answer: 9 students have an average age of 8 years so the sum of their ages is 9 * 8 = 72 years. A tenth student who is 28 years old will make the sum 72 + 28 = 100 years. The new average age will be 100 / 10 = 10 years. This is 10 - 8 = 2 years higher than the previous average.
The answer: 2
What was the question?
Question: There are 10 students in a class. The average age of 9 of them is 8 years. By how many years will this average increase if the tenth student is (quite strangely) 28 years old?


He spent 200 * 2 = $400. There were 200 * .2 = 40 tickets. Of those 40 * .8 = 32 are 5 dollar winners. So they win 32 * 5 = $160. He has 40 - 32 = 8 other winning tickets. Of those 8 - 1 = 7 wins $10. So they win 10 * 7 = $70. So he won 5000 + 70 + 160 - 400 = $4830.
The answer: 4830
Reverse engineering the question: James buys 200 lotto tickets for 2 dollars each. Of those tickets 20% are winners. 80% of the winners are for 5 dollars. 1 ticket is the grand prize of $5,000. The other tickets win an average of $10. How much did he profit?


Reasoning and answer: Joshua made 20 + 6 = 26 macarons. Miles made 26 x 2 = 52 macarons. Three - fourths of Miles' macarons is 52 x 3 / 4 = 39. So Renz made 39 - 1 = 38 macarons. The four of them have a total of 20 + 26 + 52 + 38 = 136 macarons combined. Thus, 136 / 2 = 68 kids would receive 2 macarons each.
The answer: 68
What was the question?
Question: Mitch made 20 macarons. Joshua made 6 more macarons than Mitch but half as many macarons as Miles. Renz made 1 fewer than 3/4 as many macarons as Miles. If they will combine their macarons to give them to the kids on the street, how many kids would receive 2 macarons each?


There are 3 couples in the club, so there are 3 * 2 = 6 people in couples in the club. Along with the singles and Ron and his wife, there are 6 + 5 + 2 = 13 people in the book club. There are 52 weeks in a year, so Ron gets to pick a new book 52 / 13 = 4 times a year.
The answer: 4
Reverse engineering the question: Ron is part of a book club that allows each member to take a turn picking a new book every week. The club is made up of three couples and five single people along with Ron and his wife. How many times a year does Ron get to pick a new book?


Reasoning and answer: There were 800 x 20 / 100 = 160 parents who agreed to the tuition fee increase. So, there were 800 - 160 = 640 parents who disagreed.
The answer: 640
What was the question?
Question: A survey conducted by the school showed that only 20% of the 800 parents agree to a tuition fee increase. How many parents disagree with the tuition fee increase?


Reasoning and answer: He has to read 350 pages a week because 7 x 50 = 350. He has read 262 pages because 43 + 65 + 28 + 70 + 56 = 262. He has to read 88 pages on Saturday because 350 - 262 = 88.
The answer: 88
What was the question?
Question:
Berry wants to make sure he reads an average of 50 pages a day. This week he read 43 pages on Sunday, 65 pages on Monday, and 28 pages on Tuesday. He had a soccer game and fell asleep early on Wednesday so he read nothing. On Thursday he read 70 pages, and on Friday he read 56 pages. How many pages does he have to read on Saturday to reach his goal?