Carl starts with 12 marbles to play with but loses 1 / 2, 12 / 2 = 6 marbles Carl didn't lose. Carl takes out 10 more marbles, 6 + 10 = 16 marbles. Then Carl's mother brings him 25 new marbles to add to the 16 he has out of his jar, 25 + 16 = 41 marbles that Carl is going to put in his jar after he plays his marbles game.
The answer: 41
Reverse engineering the question: Carl has a jar full of marbles. He takes out 12 marbles to play a game with, but he accidentally drops them and 1/2 the marbles get lost. So Carl takes out 10 more marbles. While he is playing his game his mother comes home with another bag of marbles for him, which has 25 marbles in it. If Carl can't find his lost marbles, then how many marbles is he going to put in the jar after he plays his game, from both his original marbles and the new ones?


Reasoning and answer: Catriona has 8 + 4 = 12 angelfish. She also has 12 x 2 = 24 guppies. Thus, she has 8 + 12 + 24 = 44 fish in her aquarium.
The answer: 44
What was the question?
Question: Catriona has 8 goldfish in her aquarium. She has 4 more angelfish than goldfish. Also, she has twice as many guppies as angelfish. How many fish does Catriona have in her aquarium?


After buying the toy, Isabel has 51 * 2 = 102 dollars left. Isabel had 102 * 2 = 204 dollars at first.
The answer: 204
Reverse engineering the question: Isabel has some money in her piggy bank. She spent half the amount and bought a toy. She then spent half of the remaining money and bought her brother a book. If she has $51 left, how much money, in dollars, did she have at first?


Reasoning and answer: He gained 2 * 3 = 6 inches. So his height is 66 + 6 = 72 inches. So he is 72 / 12 = 6 feet tall.
The answer: 6
What was the question?
Question: John was 66 inches tall. He had a growth spurt and grew 2 inches per month for 3 months. How tall is he in feet?


Betty's daughter is 40 / 100 * 60 = 24 years younger than she is. That means her daughter is 60 - 24 = 36 years old. So the granddaughter is 1 / 3 * 36 = 12 years old.
The answer: 12
Reverse engineering the question: Betty is 60 years old, and she is the oldest person in the family. Her daughter is 40 percent younger than she is, and her granddaughter is one-third her mother's age. How old is the granddaughter?


Mary spent 5 x $6 = $30 on drinks. She spent 10 x $14 = $140 on pizzas. She spent a total amount of $30 + $140 = $170. Therefore, Mary got a change of $200 - $170 = $30 after paying all the items for her pizza party.
The answer: 30
Reverse engineering the question:
Mary bought 5 boxes of drinks at $6 each box and 10 boxes of pizzas at $14 each box for her pizza party. She paid $200 for all the items. How much change did she get back?