Jon earned money baby-sitting. He spent 1/4 of the money on a guitar and then he gave 1/4 of what was left to charity. If he has $108 left, how much money did he start with?
Calculate initial spend:
Charity = 1/4 * 3/4 left = 3/16
1/4 + 3/16 = 7/16
This means he has 1 = 7/16 left
16/16 - 7/16 = 9/16
Let the starting amount be s:
If he has 108 left, then we have 9s/16 = 108
s =$192
Calculate initial spend:
Charity = 1/4 * 3/4 left = 3/16
1/4 + 3/16 = 7/16
This means he has 1 = 7/16 left
16/16 - 7/16 = 9/16
Let the starting amount be s:
If he has 108 left, then we have 9s/16 = 108
s =$192