First find Carolyn's total violin practice time by tripling her piano practice time: 20 minutes / day * 3 = 60 minutes / day. Then find the total amount of time she spends practicing each day: 60 minutes / day + 20 minutes / day = 80 minutes / day. Then find the total time she spends practicing each week: 80 minutes / day * 6 days / week = 480 minutes / week. Then find the total time she spends practicing each month: 480 minutes / week * 4 weeks / month = 1920 minutes / month.
The answer: 1920
Reverse engineering the question: Carolyn practices the piano for 20 minutes a day and the violin for three times as long. If she practice six days a week, how many minutes does she spend practicing in a month with four weeks?


Reasoning and answer: First, add the number of kosher meals to the number of vegan meals: 7 meals + 8 meals = 15 meals. Then subtract the three meals that are both kosher and vegan since they got counted twice: 15 meals - 3 meals = 12 meals. Finally, subtract that number from the total number of meals to find the number of meals that are neither kosher nor vegan: 30 meals - 12 meals = 18 meals.
The answer: 18
What was the question?
Question: Megan is delivering meals on wheels. Out of her 30 clients, 7 need vegan meals, 8 need kosher meals, and three people need meals that are both vegan and kosher. How many meals does Megan deliver that are neither kosher nor vegan?


Wendy’s dentist bill was 5 * $120 = $600. She got two fillings at a cost of 2 * $120 = $240. Thus, Wendy paid $600 - $240 - $70 = $290 for the tooth extraction.
The answer: 290
Reverse engineering the question: Wendy went to the dentist for a cleaning, two fillings, and a tooth extraction. The dentist charges $70 for a cleaning and $120 for a filling. Wendy’s dentist bill was five times the cost of a filling. What did Wendy pay for the tooth extraction?


Reasoning and answer: In 64 fluid ounces, there are 64 / 8 = 8 eight - ounce servings. Using 16 - ounce servings, Simeon now drinks 64 ounces in 64 / 16 = 4 servings. Thus, Simeon now drinks his water in 8 - 4 = 4 fewer servings per day.
The answer: 4
What was the question?
Question: Simeon drinks 64 fluid ounces of filtered water every day. He used to drink this water in 8-ounce-servings. But now, he drinks his water in 16-ounce servings. How many fewer servings per day does it now take Simeon to drink his water than it used to?


The contribution of the students amounted to $5 x 20 = $100. So Miss Grayson's class had $100 + $50 = $150 in all. The cost of the field trip amounted to $7 x 20 = $140. Therefore, the class of Miss Grayson is left with $150 - $140 = $10.
The answer: 10
Reverse engineering the question: Miss Grayson's class raised $50 for their field trip. Aside from that, each of her students contributed $5 each. There are 20 students in her class, and the cost of the trip is $7 for each student. After all the field trip costs were paid, how much is left in Miss Grayson's class fund?


Traveling 20 hours due east at 30 kilometers per hour, the ship sailed 20 * 30 = 600 kilometers the first day. If half the distance to the destination is 600 kilometers, then 2 * 600 = 1200 kilometers is the total distance from start to destination. One - third of the distance from start to destination is 1 / 3 * 1200 = 400 kilometers. Thus, the wind storm blew the ship in a westward direction for 600 - 400 = 200 kilometers.
The answer: 200
Reverse engineering the question:
On the first day of the journey, the Skipper sailed his ship halfway to the destination by traveling due east for 20 hours at a speed of 30 kilometers per hour, and then turned the ship's engines off to let them cool down. But while the engines were off, a wind storm blew his vessel backward in a westward direction. After the storm, the Skipper used his GPS device to determine the new location of the ship, and he discovered that he was only one-third of the way to his destination. How many kilometers had the ship been blown in a westward direction by the storm?