Each small piece is 6 inches because 72 / 12 = 6. Each piece is then 5 inches long after the knots are tied because 6 - 1 = 5. The three pieces tied together are now 15 inches long because 5 x 3 = 15.
The answer: 15
Reverse engineering the question: Vincent has 72 inches of rope that he wants to use for a project, but he needs to cut it into smaller pieces first. He cuts it into 12 equal length pieces, but then he realizes it's too short, so he ties three pieces together. The knots then make each piece 1 inch shorter. How long are his pieces of rope after all this?


Reasoning and answer: In one hour, Addison mountain's temperature will decrease to 3 / 4 of the temperature it is now, meaning the temperature will decrease to 3 / 4 * 84 = 63 degrees. The temperature decrease will be 84 - 63 = 21 degrees.
The answer: 21
What was the question?
Question: In one hour, Addison mountain's temperature will decrease to 3/4 of its temperature. If the current temperature of the mountain is 84 degrees, what will the temperature decrease by?


Let x be the number of toys Mandy has. Anna has 3 * x toys. Amanda has 3 * x + 2 toys. x + 3 * x + 3 * x + 2 = 142. 7 * x + 2 = 142. 7 * x = 140. x = 20.
The answer: 20
Reverse engineering the question: Anna has 3 times as many toys as Mandy and 2 fewer toys than Amanda. If they have 142 toys all together, how many toys does Mandy have?


Reasoning and answer: The club has a female group which has twice as many members as the male group, so there are 2 + 1 = 3 groups in the club. There are 18 members in the club, which means there are 18 / 3 = 6 members per group. Since the number of female members consists of two groups, then there are 6 * 2 = 12 female members in the club.
The answer: 12
What was the question?
Question: In a glee club, there are two times as many female than male members. How many female members are there if there are 18 members in the club?


Rory has 30 more jellybeans than Gigi who has 15 so Rory has 30 + 15 = 45 jellybeans. Rory has 45 jellybeans and Gigi has 15 so that's 45 + 15 = 60 jellybeans total. Lorelai has eaten three times the amount of jellybeans that both girls have so she has eaten 3 * 60 = 180 jellybeans.
The answer: 180
Reverse engineering the question: Rory has 30 more jellybeans than her sister Gigi who has 15 jellybeans. Lorelai has already eaten three times the number of jellybeans that both girls have. How many jellybeans has Lorelai eaten?


First hour: 13. Second hour:13(2) = 26. Third hour: 26(2) = 52. Total:13 + 26 + 52 = 91 questions.
The answer: 91
Reverse engineering the question:
Bob was creating a math test for an online platform. He created 13 questions in the first hour. Bob then doubled his rate for the second hour, and doubled his second hour rate for the third hour. How many questions did Bob create in the three hours?