Reasoning and answer: The sandbox has an area of 40 * 40 = 1600 square inches. To fill this area, 1600 / 80 = 20 bags of sand are needed. Then, the weight of these bags is 20 * 30 = 600 pounds.
The answer: 600
What was the question?
Question: A father is buying sand to fill his son's new sandbox, but he is worried that the sand will be too heavy for his car. The sandbox is square, with each side being 40 inches long. If a 30-pound bag of sand is enough to fill 80 square inches of the sandbox to an adequate depth, how many pounds of sand are needed to fill the box completely?


Archie needs $3 x 3 = $9 per day to buy 3 antibiotics. Therefore Archie needs $9 x 7 = $63 to buy antibiotics that will last for a week.
The answer: 63
Reverse engineering the question: Archie received his medical receipt from his doctor, and he needs to take antibiotics three times a day. If antibiotic costs $3 each and he needs to take it for a week, how much money does he need to buy the antibiotics?


Reasoning and answer: Before lunch, 24 / 3 = 8 students were photographed. Then 8 + 10 = 18 have been photographed by gym class. So 24 - 18 = 6 remain.
The answer: 6
What was the question?
Question: There are 24 students in the class. One-third had their school portraits taken before lunch. After lunch, but before gym class, 10 additional students had their portraits taken. After gym class, how many students have not yet had their picture taken?


First subtract the 8 toddlers Bill double - counted from his count: 26 toddlers - 8 toddlers = 18 toddlers. Then add the 3 toddlers he missed to find the real count: 18 toddlers + 3 toddlers = 21 toddlers.
The answer: 21
Reverse engineering the question: Bill is trying to count the toddlers at his daycare, but they keep running around. He double-counts 8 toddlers and misses 3 who are hiding. If Bill thinks he counted 26 toddlers, how many are there really?


Reasoning and answer: There are 15 x 4 = 60 slices of bread in 4 loaves of bread. Hence, each of them ate 60 / 10 = 6 slices of bread.
The answer: 6
What was the question?
Question: A loaf of bread was sliced into 15. Ten friends bought 4 loaves of bread. If they all eat all 4 loaves equally, how many slices of bread did each of them eat?


Reasoning and answer: At the highest setting, it vibrates 1600 * .6 = 960 vibrations per second faster than the lowest setting. So it vibrates at 1600 + 960 = 2560 vibrations per second. Matt uses it for 5 minutes so that is 5 * 60 = 300 seconds. That means he experienced 2560 * 300 = 768,000 vibrations.
The answer: 768000
What was the question?
Question:
Matt buys a massager. At the lowest setting, it vibrates at 1600 vibrations per second. At the highest setting, it vibrates 60% faster. Matt uses it for 5 minutes at the highest setting. How many vibrations does he experience?