Last year the librarian bought 300 + 100 = 400 books. Thus, there were 500 + 300 + 400 = 1200 books as of last year. Therefore, there are 1200 - 200 = 1000 books now in the library.
The answer: 1000
Reverse engineering the question: Five years ago, there were 500 old books in the library. Two years ago, the librarian bought 300 books. Last year, the librarian bought 100 more books than she had bought the previous year. This year, the librarian donated 200 of the library's old books. How many books are in the library now?
Reasoning and answer: Marcel bought 10 ears of corn and Dale bought 1 / 2 what Marcel did, 10 x 1 / 2 = 10 / 2 = 5 ears of corn that Dale bought. Together, Marcel and Dale bought 10 + 5 = 15 ears of corn, or 15 vegetables. They end up buying 27 vegetables total, and from those 27, 15 of them were corn. The rest of the vegetables are potatoes, 27 vegetables - 15 ears of corn = 12 potatoes. Dale bought 8 potatoes, so Marcel bought 12 - 8 = 4 potatoes.
The answer: 4
What was the question?
Question: Marcel goes to the store with Dale to buy groceries for cooking dinner. Marcel buys 10 ears of corn, and Dale buys half that amount. Dale buys 8 potatoes and Marcel buys some, too. If they check out together and end up buying 27 vegetables, how many potatoes did Marcel buy?
Let V be the number of yards of velvet fabric Louis bought. The silver thread cost 2 * 3 = $6. He spent 24V + 15 + 6 = $141 on the suit. The fabric cost 24V = 141 - 15 - 6 = $120. Thus, Louis bought V = 120 / 24 = 5 yards of fabric.
The answer: 5
Reverse engineering the question: Louis is making himself a velvet suit for a formal event. The velvet fabric he chose was $24 per yard. He bought a pattern for $15, and two spools of silver thread for $3 each. If he spent $141 for the pattern, thread, and fabric, how many yards of fabric did he buy?
Reasoning and answer: Gerry's raft needs (36 / 3) x 2 = 12 x 2 = 24 sticks. Simon and Gerry's rafts need 36 + 24 = 60 sticks. Micky's raft needs 60 + 9 = 69 sticks. The boys need to collect 60 + 69 = 129 sticks in total.
The answer: 129
What was the question?
Question: Simon, Gerry, and Micky want to have a race with handmade miniature rafts. Simon's raft needs 36 sticks, Gerry's raft needs two-thirds of the number of sticks that Simon needs, and Micky's raft needs 9 sticks more than Simon and Gerry's rafts combined. How many sticks do the three boys need to collect in total?
His first mile was in 6 minutes, then 5 minutes, another 5 minutes and his final mile was 4 minutes so it took him 6 + 5 + 5 + 4 = 20 minutes. It took 20 minutes to run 4 miles so his average time was 20 / 4 = 5 minutes per mile.
The answer: 5
Reverse engineering the question: Colin ran his first mile in 6 minutes. He ran his next two miles in 5 minutes each and finished his 4th mile in 4 minutes. What was the average time it took him to run a mile?
If Rhett is currently paid $5000 per month, he pays 10 / 100 * $5000 = $500 in taxes. Rhett has been late on two of his monthly rent payments and plans to pay them with 3 / 5 * $4500 = $2700 from his salary after taxes. If he is to pay $2700 for two late monthly rent payments, his monthly rent expense is $2700 / 2 = $1350.
The answer: 1350
Reverse engineering the question:
Rhett has been late on two of his monthly rent payments, but his landlord does not charge late fees and so he will be able to pay their total cost with 3/5 of his next month's salary after taxes. If he is currently paid $5000 per month and has to pay 10% tax, calculate his rent expense per month?