Math
posted by Barb .
A merchant visited 3 fairs. At the first, he doubled his money and spent $30; at the second he tripled his money and spent $54; at the third, he quadrupled his money and spent $72, and then had $48 left. How much money had he at the start?

$29
29x2=58
5830=28
28x3=84
8454=30
30x4=120
12072=48