The first choice is to get a penny on day one, two pennies on day two, four pennies on day three, and so on, doubling every day.

The second choice is to get a dollar on day one, two dollars on day two, three dollars on day three, and so on, adding a dollar each day.

Jill decides to get double each day starting with a penny and Jack decides to get an extra dollar each day.

After three weeks, who has more money?

What if Jack started with two dollars and received an extra two dollars each day? How about ten extra dollars each day?