Since one - third of the class participated, there are 39 * 1 / 3 = 13 students who participated in the competition. This means that 39 13 = 26 students did not participate.
The answer: 26
Reverse engineering the question: One-third of a class of 39 students took part in a math competition. How many students did not participate in the competition?
Reasoning and answer: Patty: 12 / 3 = 4 hours. Rachel: 5 + 2(4) = 13 hours.
The answer: 13
What was the question?
Question: Matt can paint a house in 12 hours. Patty can paint the same house in one third the time. Rachel can paint the same house in 5 more than double the amount of hours as Patty. How long will it take Rachel to paint the house?
Uncle Ben has 440 chickens - 39 roosters = 401 hens. Uncle Ben has 401 hens - 15 that don't lay eggs = 386 hens that lay eggs. The egg - laying hens each lay 3 eggs * 386 hens = 1158 eggs.
The answer: 1158
Reverse engineering the question: Uncle Ben has 440 chickens on his farm. 39 are roosters and the rest are hens. 15 of his hens do not lay eggs, and the rest do. If each egg-laying hen lays 3 eggs, how many eggs will Uncle Ben have?
Reasoning and answer: Let U = the number of videos Uma watched. Ekon = U - 17. Kelsey = (U - 17) + 43 = U + 26. U + U - 17 + U + 26 = 411. 3U + 9 = 411. 3U = 402. U = 134. Kelsey = 134 + 26 = 160 videos. Kelsey watched 160 videos.
The answer: 160
What was the question?
Question: Together 3 friends watched 411 short videos. Kelsey watched 43 more than Ekon. Ekon watched 17 less than Uma. How many videos did Kelsey watch?
He reads 2 * 50 = 100 pages a day. So he reads 7 * 100 = 700 pages a week. So it takes 2800 / 700 = 4 weeks.
The answer: 4
Reverse engineering the question: John reads his bible every day. He reads for 2 hours a day and reads at a rate of 50 pages an hour. If the bible is 2800 pages long how many weeks will it take him to read it all?
The sum is 9 + 14 + 13 = 36. There are 3 bouquets. The average is 36 / 3 = 12.
The answer: 12
Reverse engineering the question:
Trevor buys several bouquets of carnations. The first included 9 carnations; the second included 14 carnations; the third included 13 carnations. What is the average number of carnations in the bouquets?