Mary's parents decide to give her an allowance every Saturday. The first Saturday they give her .01 cent. For each successive week they double the amount given the previous week. If Mary saves her allowance, in how many weeks will she be a millionaire?
0.01
0.02
0.04
0.08
0.16
Keep doubling it. You'd be surprised how short a time it will take for her to be a millionaire.