Since the father dug a hole with a rate of 4 feet per hour, if the father took 400 hours digging the hole, he dug a hole 4 * 400 = 1600 feet deep. Twice the depth of the hole that Michael's father dug is 2 * 1600 = 3200 feet. Michael wants to dig a hole 400 feet less than twice the depth of the hole that his father dug, meaning he wants to dig a hole 3200 - 400 = 2800 feet deep. To dig a hole that is 400 feet less than twice as deep as his father's hole working at a rate of 4 feet per hour, Michael will have to work for 2800 / 4 = 700 hours.
The answer: 700
Reverse engineering the question: Michael wants to dig a hole 400 feet less deep than twice the depth of the hole that his father dug. The father dug a hole at a rate of 4 feet per hour. If the father took 400 hours to dig his hole, how many hours will it take for Michael to dig a hole that is 400 feet less than twice as deep as his father's hole working at the same rate?
Reasoning and answer: First subtract the cost of Mark's groceries from the amount he gives the cashier to find how much he gets in change: $7.00 - $4.20 - $2.05 = $0.75. Then subtract the value of a quarter in cents (25) and the value of a dime in cents (10) from the change amount to find how much Mark gets paid in nickels: $0.75 - $0.25 - $0.10 = $0.40. Now divide the amount Mark gets in nickels by the value per nickel in cents (5) to find how many nickels Mark gets: $0.40 / $0.05 / nickel = 8 nickels.
The answer: 8
What was the question?
Question: Mark buys a loaf of bread for $4.20 and some cheese for $2.05. He gives the cashier $7.00. If the cashier only has 1 quarter and 1 dime in his till, plus a bunch of nickels, how many nickels does Mark get in his change?
Wyatt has 10 - 4 = 6 yellow envelopes. The total number of envelopes he has is 10 blue + 6 yellow = 16 envelopes.
The answer: 16
Reverse engineering the question: Wyatt has 10 blue envelopes. He has 4 fewer yellow envelopes than blue envelopes. How many envelopes does Wyatt have in all?
Reasoning and answer: Rick has one less than three stripes, or 3 - 1 = 2 stripes on each tennis shoe. Hortense has double the 3 stripes that Olga has, or a total of 3 * 2 = 6 stripes per shoe. Since each of them has two tennis shoes per pair, then the total number of stripes on all of their shoes is 2 * (3 + 2 + 6) = 22 stripes.
The answer: 22
What was the question?
Question: Olga has three stripes on the side of each of her tennis shoes. Rick has one less stripe per shoe than does Olga. But Hortense has double the number of stripes on her tennis shoes as does Olga. In total, what is the combined number of stripes on all of their pairs of tennis shoes?
We have 60 minutes per hour. So, in 24 hours we have 60 * 24 = 1440 minutes. So, the volume of air Ross inhaled in 24 hours is: 17 breaths / minute * 5 / 9 L / breath * 1440 minutes = 122400 / 9 = 13600 liters. The volume of air inhaled is 13600 liters.
The answer: 13600
Reverse engineering the question: Ross takes 17 breaths per minute by inhaling 5/9 liter of air to his lungs. What is the volume of air inhaled in 24 hours?
Roberto skips 70 times per minute because 4,200 / 60 = 70. Together they skip 150 times a minute. They will skip 2,250 times because 150 x 15 = 2,250.
The answer: 2250
Reverse engineering the question:
Roberto and Valerie are jumping rope at recess. Roberto can skip 4,200 times an hour. Valerie can skip 80 times a minute. If they jump rope for fifteen minutes straight, how many skips will they total?