Kenny ran for 10 * 2 = 20 hours. Kenny practiced the trumpet for 20 * 2 = 40 hours.
The answer: 40
Reverse engineering the question: Kenny played 10 hours of basketball last week. He ran for twice as long as he played basketball, and he practiced on the trumpet for twice as long as he ran. How many hours did Kenny practice on the trumpet last week?

Donna can finish a total of 8 x 5 = 40 episodes during the weekdays. Meanwhile, she can finish 8 x 3 = 24 episodes each day during the weekend. The total number of episodes she can watch every weekend is 24 x 2 = 48. Therefore, Donna can watch 40 + 48 = 88 episodes every week.
The answer: 88
Reverse engineering the question: Donna can watch 8 episodes each day during weekdays. On each weekend day, she can watch three times the number of episodes she can watch on the weekdays. How many episodes can she watch in a week?

From the 4 boxes, Nori had 8 * 4 = 32 crayons. After giving 5 crayons to Mae, she had 32 - 5 = 27 crayons left. If she only has 15 crayons now, this means she gave Lea 27 - 15 = 12 crayons. Hence, Lea has 12 - 5 = 7 more crayons than Mae.
The answer: 7
Reverse engineering the question: Nori had 4 boxes of crayons with 8 crayons in each box. She gave 5 crayons to Mae and also give some crayons to Lea. How many more crayons did she give to Lea than Mae if she has only 15 crayons left?

First find the total number of starfish arms: 7 starfish * 5 arms / starfish = 35 arms. Then add the number of seastar arms to find the total number of arms: 35 arms + 14 arms = 49 arms.
The answer: 49
Reverse engineering the question:
Carly collected 7 starfish with 5 arms each and one seastar with 14 arms. How many arms do the animals she collected have in total?