The writer is going to write 518 questions + 476 questions = 994 questions in 7 days. He should aim to do 994 questions ÷ 7 days = 142 questions / day.
The answer: 142
Reverse engineering the question: A mathematician is working on two projects. He has one week to write 518 maths questions for one project and 476 questions for another project. If he completes the same number of questions every day, how many should he aim to complete each day?


Reasoning and answer: 8 pints of paint cost $8.00 each so they would cost her 8 * 8 = $64.00. 8 pints of paint cost $64.00 or she could buy a gallon of paint for $55.00. If she buys a gallon, she will save 64 - 55 = $9.00.
The answer: 9
What was the question?
Question: Christine figures it would take a pint of paint to paint the front and back of 1 door in her house. She has 8 doors to paint. At the paint store, she can either buy 8 separate pints of paint for $8.00 a pint or a gallon of paint (which is the same as 8 pints) for a flat $55.00 How much money will she save if she buys the gallon of paint instead of 8 pints?


Since Marlon spent half of the gift card, then half of it which is $200 / 2 = $100 remained on Monday. Then on Tuesday, he spent $100 / 4 = $25. Therefore, he has $100 - $25 = $75 left in his gift card.
The answer: 75
Reverse engineering the question: Marlon has a gift card for $200. He spent half of it on Monday and one-fourth of the remainder on Tuesday. How much was left on his gift card?


Reasoning and answer: Let x be the number of red marbles. 5 * x = x + 24. 4 * x = 24. x = 6.
The answer: 6
What was the question?
Question: Brett has 24 more blue marbles than red marbles. He has 5 times as many blue marbles as red marbles. How many red marbles does he have?


First find the number of pups in the first generation: 8 mice * 6 pups / mouse = 48 pups. Then add the number of adult mice to find the total number of mice: 48 pups + 8 mice = 56 mice. Then find the number of pups per mouse that survive from the second generation: 6 pups / mouse - 2 pups / mouse = 4 pups / mouse. Then multiply that number by the number of adult mice to find the number of pups in the second generation: 56 mice * 4 pups / mouse = 224 mice. Then add the number of adult mice to the number of second - generation pups to find the total number of mice: 224 mice + 56 mice = 280 mice.
The answer: 280
Reverse engineering the question: Billy is breeding mice for an experiment. He starts with 8 mice, who each have 6 pups. When the pups grow up, all the mice have another 6 pups. Then each adult mouse eats 2 of their pups due to the stress of overcrowding. How many mice are left?


At least one person lives in 85 / 100 * 120 = 102 apartments. At least two persons live in 60 / 100 * 120 = 72 apartments. So in every of the 102 - 72 = 30 apartments, only one person is living.
The answer: 30
Reverse engineering the question:
In a block of flats, there are 120 apartments. 85% of them have at least 1 resident, while 60% of the apartments have at least two residents. How many apartments have only one resident?