The dirtbikes cost 3 * 150 = $450. The off - road vehicles cost 300 * 4 = $1200. He had to register 3 + 4 = 7 vehicles. That means registration cost 25 * 7 = $175. So the total cost of everything was 450 + 1200 + 175 = $1825.
The answer: 1825
Reverse engineering the question: James buys 3 dirt bikes for $150 each and 4 off-road vehicles for $300 each. It also cost him $25 to register each of these. How much did he pay for everything?
Reasoning and answer: One hour is 60 minutes, so there can be 60 / 15 = 4 different sets of actors. This means, that during one hour there can be 4 * 5 = 20 different actors in the show.
The answer: 20
What was the question?
Question: In a show, there can be 5 actors at a time. Every actor is in the show for about 15 minutes, and then another 5 actors come in. How many actors can there be on the show in 1 hour?
The Biology class has 200 / 2 = 100 students. The boys in the Biology class are 1 / 4 * 100 = 25 students.
The answer: 25
Reverse engineering the question: There are three times as many girls as boys in the Biology class. The Physics class has 200 students. If the Biology class has half as many students as the Physics class, how many boys are in the Biology class?
Reasoning and answer: The two t - shirts amount to $8 x 2 = $16. The two bags amount to $10 x 2 = $20. So Timothy spent $16 + $20 = $36 for the shirts and bags. He still has $50 - $36 = $14 left to spend for the key chains. With the money, he can buy $14 / $2 = 7 sets of key chains. Therefore, he can buy 7 x 3 = 21 pieces of key chains.
The answer: 21
What was the question?
Question: Timothy has $50 to spend at a souvenir shop. He sees some t-shirts that cost $8 each, key chains that sell 3 pieces for $2, and bags that cost $10 each. Timothy buys 2 t-shirts and 2 bags. How many pieces of key chains can he buy with the amount of money he has left?
First find how many liters of the seawater are salt: 2 liters * 20% = .4 liters. Then multiply that amount by 1000 ml / liter to find the number of ml of salt Jack gets: .4 liters * 1000 ml / liter = 400 ml.
The answer: 400
Reverse engineering the question: Jack is stranded on a desert island. He wants some salt to season his fish. He collects 2 liters of seawater in an old bucket. If the water is 20% salt, how many ml of salt will Jack get when all the water evaporates?
After subtracting 10 from the number of turtles on Happy Island, we get 60 - 10 = 50 turtles. Dividing this number by two, we find that the number of turtles on Lonely Island is 50 / 2 = 25 turtles.
The answer: 25
Reverse engineering the question:
Happy Island has 60 turtles. This means there are 10 more than 2 times as many turtles on Happy Island as on Lonely Island. How many turtles are there on Lonely Island?