user: [Question]Every morning, Carla puts 79 apples in her backpack to eat for lunch. Unfortunately, Buffy stole some of Carla's apples on the school bus, and 26 apples fell out of a hole on the bottom. So at lunchtime, Carla only had 8 apples remaining. How many apples did Buffy steal from Carla?
[Answer]Let B be the number of apples that Buffy stole. Then 79 - B - 26 = 8. Combining constants produces 53 - B = 8. Adding B to both sides produces 52 = B + 8. Thus the number of apples stolen by Buffy is B = 53 - 8 = 45. The answer is 45.
Q: Ten friends decide to get an end-of-year gift for their teacher. They plan to split the cost of the gift equally. But four of the group drop out. The remaining friends split the cost equally among themselves. If each share is now $8 more, how much does the gift cost, in dollars?
A: Let N be the original price each friend was going to pay. 10N = 6(N + 8). 10N = 6N + 48. 4N = 48. N = 12. Then the present costs 10 * 12 = 120. The answer is 120.
Question: Colbert is building a treehouse out of wooden planks. The treehouse needs 200 wooden planks. A quarter of these planks come from Colbert’s storage, half of these planks come from Colbert’s parents, 20 planks come from Colbert’s friends and he buys the rest from the store. How many planks of wood does he need to buy from the store to finish his treehouse?
Answer: In Colbert’s storage, there are 200 wooden planks / 4 = 50 wooden planks. From his parents, there are 200 wooden planks / 2 = 100 wooden planks. So in total, Colbert has not had to buy 50 wooden planks from storage + 100 wooden planks from his parents + 20 wooden planks from his friends = 170 wooden planks. He therefore still needs to buy 200 needed wooden planks – 170 owned wooden planks = 30 wooden planks. The answer is 30.
[Question]John sublets his apartment to 3 people who each pay $400 per month. He rents the apartment for $900 a month. How much profit does he make in a year?
[Answer]He gets 3 * $400 = $1200 per month. So he gets 1200 * 12 = $14,400 per year. So he pays 12 * 900 = $10800 a year. That means his profit is 14400 - 10800 = $3600 per year. The answer is 3600.
Q: Valerie needs to put stamps on the envelopes she is about to mail. She has thank you cards for each of her grandmother, uncle and aunt for the birthday presents they sent. She also has to pay the water bill and the electric bill separately. She wants to send three more mail-in rebates than she does bills and she has twice as many job applications as rebates to mail. How many stamps does she need if everything needs 1 stamp except the electric bill, which needs 2?
A: Valerie has to send a thank you card to each of 3 people, so she has 3 * 1 = 3 thank you cards to mail. She has 2 bills to mail. She has 3 more rebates than bills, so 3 + 2 = 5 mail - in rebates to mail. She has twice as many job applications as rebates, so she has 2 * 5 = 10 applications to mail. She has 3 + 2 + 5 + 10 = 20 pieces of mail to send. The electric bill needs an extra stamp, so she needs 20 + 1 = 21 stamps. The answer is 21.
Question: Donna cut her pizza into 12 slices and ate half for lunch. She ate 1/3 of the remaining pizza for dinner. How many slices are left for Donna's lunch tomorrow?
Answer:

assistant: Her pizza has 12 slices and she ate 1 / 2 of the pizza for lunch so that leaves 12 / 2 = 6 slices left. She eats 1 / 3 of the pizza for dinner, so she eats 1 / 3 * 6 = 2 slices. She had 6 slices and ate 2 slices, so that leaves her with 6 - 2 = 4 slices for tomorrow's lunch. The answer is 4.