Jerry has 2 x 20 = 40 dice. Therefore, they have 20 + 40 = 60 dice altogether.
The answer: 60
Reverse engineering the question: Ivan has 20 dice. Jerry has twice as many dice as Ivan. How many dice do they have altogether?

Total meatballs on the plates 3 x 3 = 9. If two - thirds are eaten, one - third remaining on the plates is 9 / 3 = 3.
The answer: 3
Reverse engineering the question: There are 3 meatballs on each spaghetti plate. If Theresa's 3 sons each eat two-thirds of the meatballs on their respective plates, how many meatballs are still left on their plates altogether?

Andy weighed 156 + 36 = 192 pounds after growing taller. An eighth of his weight is 1 / 8 x 192 = 24 pounds. Over the next 3 months, Andy lost 24 x 3 = 72 pounds. He now weighs 192 - 72 = 120 pounds. Andy weighs 156 - 120 = 36 pounds less than at the beginning of the year.
The answer: 36
Reverse engineering the question: Andy started out the year weighing 156 pounds. He then grew 3 inches and gained 36 pounds. Andy wasn't happy with his weight and decided to exercise. Over the next 3 months, he lost an eighth of his weight every month. How much less does Andy weigh now than at the beginning of the year?

He works 8 hours a day for 10 days means he works 8 * 10 = 80 hours. It takes him 5 hours to build one rocking chair so over 80 hours he builds 80 / 5 = 16 rocking chairs.
The answer: 16
Reverse engineering the question:
Ben works 8-hour shifts in a furniture shop. It takes him 5 hours to build 1 rocking chair. How many chairs can he build in 10 days?