Andy blew up 50 balloons – the 12 balloons Ashley blew up = 38 balloons. We know how long it took Andy to blow up 2 balloons, so 38 balloons / 2 = 19 time increments. We know the time increment is 5 minutes, so 19 x 5 minutes = 95 minutes.
The answer: 95
Reverse engineering the question: Ashley had already blown up 12 balloons for the party when Andy took over and started blowing them up at a rate of 2 every five minutes. When Andy stopped, there were 50 balloons. For how many minutes did Andy blow up balloons?


Reasoning and answer: Two quarter - pounder burgers cost $3.20 x 2 = $6.40. Two large fries cost $1.90 x 2 = $3.80. Two milkshakes cost $2.40 x 2 = $4.80. The total amount spent for the burgers, fries, and shakes is $6.40 + $3.80 + $4.80 = $15. Therefore, he should order $18 - $15 = $3 worth of additional food to take advantage of the free food delivery.
The answer: 3
What was the question?
Question: A fast-food chain offers free delivery for a minimum purchase of $18. Danny ordered 2 quarter-pounder burgers for $3.20 each, 2 large fries that cost $1.90 each, and 2 milkshakes that cost $2.40 each. How much more worth of food should he order to avail of the free delivery?


Rose cooked 10 x 9 / 10 = 9 kilograms of rice in the morning. She had 10 - 9 = 1 kilogram of rice left then. One kilogram is equal to 1 x 1000 = 1000 grams. So, Rose cooked 1000 x 1 / 4 = 250 grams of rice in the evening. Therefore, she has 1000 - 250 = 750 grams of rice left.
The answer: 750
Reverse engineering the question: Rose had 10 kilograms of rice. She cooked 9/10 kilograms in the morning and 1/4 of the remaining in the evening. How many grams of rice did she have left?


Reasoning and answer: Bellas has 100% / 25% = 4 times less earrings than Monica. This means that Monica has 10 * 4 = 40 earrings. Rachel has two times fewer earrings than Monica, which means 40 / 2 = 20 earrings. So all three friends, have a total of 10 + 40 + 20 = 70 earrings.
The answer: 70
What was the question?
Question: Bella, Monica, and Rachel are friends who like jewelry. Bella has 10 earrings, which is 25% of Monica's earrings, and Monica has twice as many earrings as Rachel. How many earrings do all of the friends have?


The contractor works for 3 * 5 = 15 hours. That means he charged 150 * 15 = $2250. The inspector charged 2250 * .8 = $1800 less. So the inspector charged 2250 - 1800 = $450. So the total amount charged was 250 + 450 + 2250 = $2950.
The answer: 2950
Reverse engineering the question: John decides to install a ramp in his house. He needs to get permits which cost $250. After that, he hires a contractor which costs $150 an hour and the guy works for 3 days at 5 hours per day. He also pays an inspector 80% less to make sure it is OK. How much was the total cost?


Larry spends 30 * 2 = 60 minutes per day walking his dog. Larry spends 60 / 5 = 12 minutes every day feeding his dog. Larry spends 60 + 12 = 72 minutes per day on his dog.
The answer: 72
Reverse engineering the question:
Larry spends half an hour twice a day walking and playing with his dog. He also spends a fifth of an hour every day feeding his dog. How many minutes does Larry spend on his dog each day?