Question

Will someone please help me solve this? A girl scout troop sold cookies. If the girls sold 5 more boxes the second week than they did the first, and if they doubled the sales of the second week for the third week to sell a total of 431 boxes of cookies, how many did they sell each week?

Answer 1

1. 104 boxes
2. 109 boxes
3. 218 boxes

Explanation:

Let b represent the number of boxes of cookies sold the first week. Then b+5 boxes were sold the second week, and 2(b+5) boxes were sold the third week. The total sold was ...

b +(b+5) +2(b+5) = 431

4b +15 = 431 . . . . . . simplify

b = (431 -15)/4 = 104 . . . . . subtract 15, divide by the coefficient of b

First week: b = 104

Second week: b+5 = 109

Third week: 2(b+5) = 218