Reasoning and answer: The tax was 200 * .15 = $30. So he paid 200 + 30 = $230.
The answer: 230
What was the question?
Question: John buys a pair of earbuds that cost $200. If tax was 15%, how much did he pay after tax?


If each lap is 400 meters long, then 3 laps will have a total distance of 400 * 3 = 1200 meters. The total time he ran was 70 on the first lap + 85 on the second one and 85 on the third lap, so his total running time was = 70 + 85 + 85 = 240 seconds. His average speed then is measured by the total distance he ran (1200) divided by the total time required (240) or 1200 / 240 = 5 m / s.
The answer: 5
Reverse engineering the question: Bob's school track is 400 meters. If Bob ran the first lap in 70 seconds, the second and third lap in 85 seconds each, what was his average speed in (m/s) for his entire run?


Reasoning and answer: In the first three turns, Susan has moved 8 + 2 - 5 + 6 = 11 spaces. Susan has 48 - 11 = 37 spaces to move to win the game.
The answer: 37
What was the question?
Question: Susan is playing a board game with 48 spaces from the starting space to the winning end space of the game. On the first turn, she moves forward eight spaces. On the second turn, she moves two spaces, but lands on a space that sends her back five spaces. On the third turn, she moves forward six more spaces. How many spaces does she have to move to reach the ending space and win the game?


First, the 144 acres of grass will be eaten according to the equation 5 * 2 * T + 8 * 1 * T = 144. Solving this equation for T, we find 18 * T = 144, or T = 8 months of food are covered by the animals grazing on the rancher's pasture. This means the farmer must buy feed corn for the remaining 12 - 8 = 4 months. Next, the rancher's 8 sheep will require 4 / 2 = 2 bags of feed corn each, or 8 * 2 = 16 bags of feed corn in total for the 4 month period. The rancher's 5 cows will require 4 / 1 = 4 bags of feed corn each, or 5 * 4 = 20 bags of feed corn in total for the month. Therefore, the rancher needs 16 + 20 = 36 bags of feed corn for all of his animals. So, the rancher will need to spend 36 * 10 = $360 per year on feed corn.
The answer: 360
Reverse engineering the question: A rancher owns a mixture of 8 sheep and 5 cattle that graze on his land. In a typical year, the rancher will allow his animals to feed off his pastures for as long as possible before they run out of grass. After the pastures run out of grass, he must buy feed corn for $10 per bag. Each cow eats 2 acres of grass per month, and each sheep eats 1 acre of grass per month. Additionally, a bag of feed corn can feed each cow for 1 month and each sheep for 2 months.  If the rancher's pasture contains 144 acres of grass, how much will the rancher need to spend on feed corn to feed his animals each year?


Reasoning and answer: Let x represent the youngest brother. Middle brother:x + 1. Oldest brother:x + 2. Total:x + x + 1 + x + 2 = 96. 3x + 3 = 96. 3x = 93. x = 31 years old.
The answer: 31
What was the question?
Question: The ages of three brothers are consecutive integers with the sum of 96. How old is the youngest brother?


Reasoning and answer: Lenny has 20 x 5 = 100 pens. She gave her close friends 100 x 40% = 40 pens. So, 100 - 40 = 60 pens were left. Half of 60 is 60 / 4 = 15 pens. Thus, Lenny has 60 - 15 = 45 pens left.
The answer: 45
What was the question?
Question:
Lenny bought 20 boxes of pens. Each box contained 5 pens. She gave 40% of the pens to her close friends and one-fourth of what's left to her classmates. How many pens were left for Lenny?