Reasoning and answer: First find the time difference per problem: 5 minutes / problem - 2 minutes / problem = 3 minutes / problem. Then multiply that number by the number of problems to find the total time difference: 3 minutes / problem * 20 problems = 60 minutes.
The answer: 60
What was the question?
Question: It takes Matt 2 minutes per problem to do his math homework with a calculator and 5 minutes per problem without a calculator. If Matt's assignment has 20 problems, how much time will using a calculator save?

Reasoning and answer: He can jump 3 * 60 = 180 times per minute. So he can jump 180 * 60 = 10,800 per hour. So it would take him 54,000 / 10,800 = 5 hours.
The answer: 5
What was the question?
Question: Mark wants to set the record for most consecutive ropes jumped. The record is 54,000. He can jump 3 times a second. How many hours would he need to jump rope?

Reasoning and answer: The chickens had 7 * 2 = 14 legs. The sheep had 5 * 4 = 20 legs. There were 14 + 20 = 34 legs.
The answer: 34
What was the question?
Question:
Farmer Brown fed 7 chickens and 5 sheep. How many total legs were there among the animals he fed?