Question

Coby sells apples and bananas at his fruit store. He charges $6 for a bunch of bananas, and $8 for a pound of apples. If a customer buys a total of 13 pieces of fruit and is charged $92, how many bunches of bananas did he buy? Also, how many pounds of apples did he get?

Answer 1

• 6 bunches of bananas
• 7 pounds of apples

Explanation:

We have to assume that a "piece of fruit" is either a bunch of bananas or a pound of apples. Without that assumption, there is insufficient information to work the problem.

Let B represent the number of bunches of bananas. Then 13-B is the number of pounds of apples. The total cost is ...

6B +8(13 -B) = 92

-2B + 104 = 92 . . . . . eliminate parentheses

B = -12/-2 = 6 . . . . . . subtract 104, then divide by the coefficient of B

13-B = 7 . . . . . . . . . . . the number of pounds of apples

The customer bought 6 bunches of bananas and 7 pounds of apples.

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Comment on the solution

You will note that finding the value of the variable involved arithmetic with negative numbers. If you want the numbers to stay positive, then you can choose the variable to represent the most expensive of the items: the number of pounds of apples.