Frank bought supplies for school. In the first store, he spent half of his money plus $10. In the second store, he spent half of what he had left, plus $10. In the third store, he spent 80% of what he had left. He came home with $5. How much did he start out with?

Question

Frank bought supplies for school.  In the first store, he spent half of his money plus $10.  In the second store, he spent half of what he had left, plus $10.  In the third store, he spent 80% of what he had left.  He came home with $5.  How much did he start out with?

1. store~x/2+10
2. store~(x-(x/2+10)/2)+10
3.store~(x)(4/5)

answer is -35

Steve · Accepted Answer

y = x/2+10 z = (x-y)/2+10 1/5 (x-y-z) = 5 x = 160 check: he spent 160/2+10 = 90, leaving 70 he spent 70/2+10 = 45, leaving 25 he spent .80*25 = 20, leaving 5