He has seen 48 chimp legs because 12 x 4 = 48. He has seen 32 lion legs because 8 x 4 = 32. He has seen 20 lizard legs because 5 x 4 = 20. He has seen 100 total legs because 48 + 32 + 20 = 100. He has to see 1000 tarantulas legs because 1100 - 100 = 1000. He has to see 125 tarantulas because 1000 / 8 = 125.
The answer: 125
Reverse engineering the question: Borgnine wants to see 1100 legs at the zoo. He has already seen 12 chimps, 8 lions, and 5 lizards. He is next headed to see the tarantulas. How many tarantulas does he need to see to meet his goal?


Reasoning and answer: If Olive charges her phone for 3 / 5 of the time she charged the phone last night, the phone would be charged for 3 / 5 * 10 = 6 hours. Assuming each hour of charge lasts the phone 2 hours of use, the phone will last for 6 * 2 = 12 hours before it goes off when Olive uses it on a six hours charge.
The answer: 12
What was the question?
Question: Last night, Olive charged her phone for 10 hours. Assuming each hour of charge lasts the phone 2 hours of use, calculate the total time Olive would be able to use her phone before it goes off if she charges it for 3/5 of the time she charged the phone last night.


The price of the bicycle increased by $220 * 15 / 100 = $33. Adding the increment price, the new price is $220 + $33 = $253.
The answer: 253
Reverse engineering the question: The selling price of a bicycle that had sold for $220 last year was increased by 15%. What is the new price?


Reasoning and answer: First figure out how much water beans take by multiplying the water use for corn by 2: 20 gallons / acre * 2 = 40 gallons / acre. Next, calculate Bob's water use by multiplying each plant's water use per acre by the number of acres he planted, then adding up the total water use for all three crops: 3 * 20 + 9 * 80 + 12 * 40 = 1260. Now do the same thing for Brenda: 6 * 20 + 7 * 80 + 14 * 40 = 1240. And do the same thing for Bernie: 2 * 20 + 12 * 80 = 1000. Now add up each farmer's water use to find the total water use: 1260 + 1240 + 1000 = 3500. Now divide Bob's water use by the total water use and multiply by 100 to find what percentage of the water he used: 1260 / 3500 * 100 = 36%.
The answer: 36
What was the question?
Question: Cary is an engineer in charge of designing an irrigation system for three farmers. Farmer Bob grows 3 acres of corn, 9 acres of cotton, and 12 acres of beans. Farmer Brenda grows 6 acres of corn, 7 acres of cotton, and 14 acres of beans. Farmer Bernie grows 2 acres of corn and 12 acres of cotton. If corn takes 20 gallons of water an acre, cotton takes 80 gallons of water an acre, and beans take twice as much water as corn, what percentage of the total water used will go to Farmer Bob's farm?


From the carwash, Hank donates $100 * 0.90 = $90. From the bake sale, Hank donates $80 * 0.75 = $60. From mowing lawns, Hank donates $50 * 1.00 = $50. Hank donates a total of $90 + $60 + $50 = $200.
The answer: 200
Reverse engineering the question: Hank is raising money for the local homeless shelter. Hank makes $100 in a carwash and donates 90% of the proceeds to the local homeless shelter. Hank makes $80 in a bake sale and donates 75% of the proceeds to the local homeless shelter. Then he makes $50 mowing lawns and donates 100% of the proceeds to the local homeless shelter. How much money does Hank donate in total?


There are four sides to a rectangle, the width is W and so the length is 2W, and we can put that in this equation: W + W + 2W + 2W = 30 feet. If we add the sides together, we get 6W = 30 feet. To find W, we divide both sides by 6, like this: 6W / 6 = 30 feet / 6, so W = 5 feet.
The answer: 5
Reverse engineering the question:
Josh built his little brother a rectangular sandbox. The perimeter of the sandbox is 30 feet and the length is twice the width. What is the width of the sandbox?