The first 8 years cost 8 * 10,000 = $80,000. The next 18 - 8 = 10 years. They cost 10000 * 2 = $20,000 per year. So they cost 20,000 * 10 = $200,000. So the cost was 200,000 + 80,000 = $280,000. Adding in the cost of tuition brings the cost to 250,000 + 280,000 = $530,000. Since John pays for half the cost of raising the child, he pays $530000 / 2 = 265000.
The answer: 265000
Reverse engineering the question: John pays for half the cost of raising a child. It cost $10,000 a year for the first 8 years and then twice that much per year until the child is 18. University tuition then costs $250,000. How much did it cost?


Reasoning and answer: Let X be the age of the older friend. The younger friend is X - 2 years old. So, the age of both is X + (X - 2) = 74. X + X = 74 + 2. 2 * X = 76. Then, the older friend is X = 38 years old.
The answer: 38
What was the question?
Question: The difference between the ages of two friends is 2 years. The sum of their ages is 74 years. Find the age of the older friend.


The sum of black and white shirts is 63 + 42 = 105. The number of jeans in the store is (2 / 3) x 105 = 70. The sum of ties and belts is 34 + 40 = 74. The number of scarfs in the store is 74 / 2 = 37. There are 70 - 37 = 33 more jeans than scarfs in the store.
The answer: 33
Reverse engineering the question: A clothing store has an inventory of 34 ties, 40 belts, 63 black shirts, and 42 white shirts. The number of jeans in the store is two-thirds of the sum of black and white shirts, and the number of scarves is half the number of the sum of ties and belts. How many more jeans are there than scarves?


Reasoning and answer: The shampoo and conditioner cost $10 each so 2 * $10 = $20.00. 3 bottles of lotion cost $6.00 each so 3 * $6 = $18.00. So far she has spent $20 + $18 = $38.00. You need to spend $50.00 for free shipping and she has spent $38.00 already so she needs to buy $50 - $38 = $12.00 more in products.
The answer: 12
What was the question?
Question: Jackie's favorite cosmetic company was offering free shipping when you spent $50.00. Jackie ordered her favorite shampoo and conditioner that each cost $10.00 a bottle and 3 bottles of lotion that cost $6.00 each. How much more money does Jackie need to spend to be eligible for free shipping?


At first, the children have 10 * 7 = 70 books. With their teacher, they have 70 + 8 = 78 books.
The answer: 78
Reverse engineering the question: In a classroom, 10 children have 7 books each. Their teacher brings another 8 books to the classroom. How many books are in the classroom altogether?


There are 60 goldfish because 15 / .25 = 60. 75% of the fish are below the surface because 100 - 25 = 75. There are 45 goldfish below the surface because 60 x .75 = 45.
The answer: 45
Reverse engineering the question:
Toby is counting goldfish in the local pond. He knows that only 25% of goldfish are at the surface and the rest are too deep below the surface to be able to see. If he counts 15 goldfish, how many are below the surface?