He spent 15 + 18 = 33 minutes doing homework. David spent 60 - 33 = 27 minutes reading.
The answer: 27
Reverse engineering the question: David finished his homework in 60 minutes. He spent 15 minutes on his math homework and 18 minutes on his spelling homework. He spent the rest of the time reading for his daily reading log. How many minutes did he spend reading?


Reasoning and answer: He buys 4 bags of frozen vegetables for $2.00 a bag so that’s 4 * 2 = $8.00. The meat is $5.00, the crackers are $3.50, the vegetables are $8.00 and the cheese is $3.50 for a total of 5 + 3.50 + 8 + 3.50 = $20.00. He gets 10% discount on his $20.00 purchase so that’s .10 * 20 = $2.00 off. His final grocery bill will be 20 - 2 = $18.00.
The answer: 18
What was the question?
Question: Ray buys a pack of hamburger meat for $5.00, a box of crackers for $3.50, 4 bags of frozen vegetables at $2.00 per bag and a pack of cheese for $3.50 at the grocery store. Because he is a store rewards member, he gets 10% off of his purchase. What does his total grocery bill come to?


In order for everyone to have seconds, Luther must make 8 x 2 = 16 pancakes. Luther must make another 16 - 12 = 4 pancakes.
The answer: 4
Reverse engineering the question: Luther made 12 pancakes for breakfast. His family has 8 people. How many more pancakes must he make for everyone to have a second pancake?


Reasoning and answer: The number of rolls already sold is 1 + 10 + 6 = 17. Nellie needs to sell 45 − 17 = 28 more rolls of gift wrap.
The answer: 28
What was the question?
Question: For a fundraiser, Nellie needs to sell 45 rolls of gift wrap. So far, she has sold 1 roll to her grandmother, 10 rolls to her uncle, and 6 rolls to a neighbor. How many more rolls of gift wrap does Nellie need to sell?


The number of black shirts is 3 × 5 = 15. The number of yellow shirts is 3 × 2 = 6. Mandy bought 15 + 6 = 21 shirts.
The answer: 21
Reverse engineering the question: Mandy bought 3 packs of black shirts and 3 packs of yellow shirts for her tennis team. The black shirts come in packs of 5, and the yellow shirts come in packs of 2. How many shirts did Mandy buy in all?


If there are six chairs in each row in the church, the total number of chairs in the church is 6 * 20 = 120. Since each chair holds 5 people, 5 * 120 = 600 people must sit in all of the chairs for the church to be full.
The answer: 600
Reverse engineering the question:
There are six chairs in each row in a church. If there are 20 rows of chairs in the church, and each chair holds five people, calculate the number of people who have to sit in the chairs for the church to be full.