Let x be the number of books in Susan's collection. The collection of both Susan and Lidia would then be 4 * x + x = 3000. 5 * x = 3000. x = 600.
The answer: 600
Reverse engineering the question: Lidia has a collection of books. Her collection is four times bigger than the collection which her friend Susan has. In total Susan and Lidia, both have 3000 books. How many books does Susan have in her collection?


Reasoning and answer: Two white socks cost 25 cents more than a single brown sock, meaning a brown sock is sold at $0.45 - $0.25 = $0.20. The cost of buying 15 brown socks is 15 * $0.20 = $3.
The answer: 3
What was the question?
Question: Two white socks cost 25 cents more than a single brown sock. If two white socks cost 45 cents, how much would you pay for 15 brown socks?


Let P be the number of pages in the first chapter. The second chapter has P + 3 pages. The third chapter has P + 3 + 3 = P + 6 pages. The fourth chapter has P + 6 + 3 = P + 9 pages. The fifth chapter has P + 9 + 3 = P + 12 pages. The whole book has P + 3 + P + 6 + P + 9 + P + 12 = 5P + 30 = 95 pages. Thus, without the 30 extra pages from additional chapters, 5P = 95 - 30 = 65 pages. Therefore, the first chapter had P = 65 / 5 = 13 pages.
The answer: 13
Reverse engineering the question: Rita is reading a five-chapter book with 95 pages. Each chapter has three pages more than the previous one. How many pages does the first chapter have?


Reasoning and answer: Two schools can teach 400 students, so in total, they can teach 2 * 400 = 800 students. The other two schools can teach 340 students, which gives 2 * 340 = 680 students in total. So all four schools can teach 800 + 680 = 1480 students at a time.
The answer: 1480
What was the question?
Question: In a town, there are four primary schools. Two of them can teach 400 students at a time, and the other two 340 students at a time. How many students at a time in total, can these four primary schools teach?


Tom had 10 x 5 = 50 miniature racing cars. Tom gave 50 x 1 / 5 = 10 miniature racing cars to each of his two nephews. So, he gave a total of 10 x 2 = 20 cars to his two nephews. Therefore, Tom is left with 50 - 20 = 30 miniature racing cars.
The answer: 30
Reverse engineering the question: Tom bought 10 packages of miniature racing cars. Each package contains five cars. He gave each of his two nephews 1/5 of the cars. How many miniature racing cars are left with Tom?


The amount paid to the teacher per day is 5 periods * $5 / period = $25 per day. The amount paid for 24 days is $25 / day * 24 days = $600. The total amount for 6 months is $600 * 6 = $3600.
The answer: 3600
Reverse engineering the question:
A teacher teaches 5 periods a day and works 24 days a month. He is paid $5 per period. if he has been working for 6 months now how much has he earned in total?