If Sebastian is 40 years old and 10 years older than his sister, his sister is 40 - 10 = 30 years old. Five years ago, Sebastian was 40 - 5 = 35 years old. Similarly, Sebastian's sister's age was 30 - 5 = 25 years old. The sum of their ages five years ago was 25 + 35 = 60. Five years ago, the sum of Sebastian's age and his sister's age was 3 / 4 of their father's age, meaning their father's age was 60 / 3 / 4 = 80 years. The father's age is now 80 + 5 = 85.
The answer: 85
Reverse engineering the question: Five years ago, the sum of Sebastian's age and his sister's age was 3/4 of their father's age. How old is their father today if Sebastian is 40 years old and 10 years older than his sister?
Reasoning and answer: First find how much water fills the bathtub per hour: 40 ml / minute * 60 minutes / hour = 2400 ml / hour. Then subtract the water that evaporates to find the total amount of water added per hour: 2400 ml / hour - 200 ml / hour = 2200 ml / hour. Then multiply that amount by the number of hours to find the total amount of water in the tub: 2200 ml / hour * 9 hours = 19800 ml. Then find the number of milliliters in 12 liters: 12 liters * 1000 ml / liter = 12000 ml. Then subtract the water Jack removes from the total amount of water to find the remaining amount of water: 19800 ml - 12000 ml = 7800 ml.
The answer: 7800
What was the question?
Question: Jack leaves his bathtub's faucet dripping at a rate of 40 ml/minute. Water evaporates from the bathtub at a rate of 200 ml/hour. If he leaves the water running for 9 hours, then dumps out 12 liters, how many milliliters of water are left in the bathtub?
Malcolm has bought 12 * 3 = 36 blue lights. This means he has bought a total of 12 + 36 + 6 = 54 colored lights. If he still needs to buy more lights, then he must have initially had 54 + 5 = 59 white lights.
The answer: 59
Reverse engineering the question: The lights in Malcolm's house are flickering, and he hopes that replacing all of his white lights with colored lights will make it stop. He buys 12 red lights, 3 times as many blue lights, and 6 green lights. If he still has 5 colored lights left to buy, how many white lights did Malcolm have initially?
Reasoning and answer: It rained 3 + 4 = 7 inches on Monday. So it rained 7 * 2 = 14 inches on Tuesday. That means the total rainfall was 7 + 14 + 4 = 25 inches.
The answer: 25
What was the question?
Question: It rained twice as much on Tuesday as Monday. On Monday it rained 3 inches more than Sunday. It rained 4 inches on Sunday. How much total rainfall was there over the 3 days?
Cary needs to save an additional $120 - $30 = $90. Cary makes $5 * 3 = $15 each weekend. It will take 90 / 15 = 6 more weekends to save enough money to afford the shoes.
The answer: 6
Reverse engineering the question: Cary is saving money to buy a new pair of shoes that cost $120. He has already saved $30. He earns $5 for every lawn he mows. If he mows 3 lawns each weekend, how many more weekends will he have to mow lawns before he can afford to buy the shoes?
There were 1150 - 150 = 1000 people who didn't vote for John. That means James got 1000 * .7 = 700 votes. So the other candidate got 1000 - 700 = 300 votes. This means he got 300 - 150 = 150 more votes than John.
The answer: 150
Reverse engineering the question:
3 people run for president. John manages to capture 150 votes. James captures 70% of the remaining vote. If there were 1150 people voting, how many more votes did the third guy get than John?