Question: The average number of fruits per basket in five baskets is 25. If basket A contains 15 apples, B has 30 mangoes, C has 20 peaches, D has 25 pears and E has some bananas, how many bananas are in basket E?
Answer: Each basket contains an average of 25 fruits so the 5 baskets in all contain 25 * 5 = 125 fruits. The number of apples, mangoes, peaches and pears is 15 + 30 + 20 + 25 = 90. The remaining fruits are bananas and they are 125 - 90 = 35 in number. The answer is 35.
[Question]Benjamin went to McDonald's to buy something for dinner. He bought a salad, a burger, and two packs of fries. He paid in total $15. How much did the burger cost, if one pack of fries was for $2 and the salad was three times that price?
[Answer]Benjamin paid for the fries 2 * 2 = $4. The salad was three times the price of one pack of fries, so it cost 3 * 2 = $6. The cost of the burger was 15 - 6 - 4 = $5. The answer is 5.
Q: As firefighters, Doug, Kai, and Eli have been putting out a lot of fires over the week. Doug has put out 20 fires for the week and Kai has put out 3 times more than Doug. Meanwhile, Eli has put out half the number of fires Kai was able to. How many fires have they put out for the entire week?
A: Kai has put out 20 x 3 = 60 fires for the week. Eli has put out 60 / 2 = 30 fires for the week. Therefore, the total amount of fires they have put out over the entire week was 20 + 60 + 30 = 110. The answer is 110.
Question: Blake goes to the grocery store and spends $40 on oranges, $50 on apples, and $60 on mangoes. If he has $300, how much change was he given?
Answer: The total costs for the fruits is $40 + $50 + $60 = $150. The amount of money given as change is $300 - $150 = $150. The answer is 150.
[Question]Nicole has 4 fish tanks. The first two tanks need 8 gallons of water each and the other two need 2 fewer gallons of water each than the first two tanks. If Nicole needs to change the water of the aquarium every week, how many gallons of water will she need in four weeks?
[Answer]The first two tanks need 8 x 2 = 16 gallons of water. The other two tanks need 8 - 2 = 6 gallons of water each. So, the two other tanks need 6 x 2 = 12 gallons of water. Nicole needs 16 + 12 = 28 gallons of water every week for her four tanks. Therefore, she needs a total of 28 x 4 = 112 gallons of water in four weeks. The answer is 112.
[Question]Ruby is taking dance lessons. They cost $75 for 10 classes in one pack. She can add additional classes at the price of 1/3 more than the average price of a class on the lesson in the pack. if she takes 13 total classes, how much does she pay?
[Answer]

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
The classes in the pack cost $7.5 each because 75 / 10 = 7.5. An additional class costs $10 because 7.5 x (1 + (1 / 3)) = 10. She buys 3 extra classes because 13 - 10 = 3. Her three additional classes cost $30 because 3 x 10 = 30. Her total cost is $105 because 75 + 30 = 105. The answer is 105.