Exponential Allowance Riddle

Initializing live version
Download to Desktop

Requires a Wolfram Notebook System

Interact on desktop, mobile and cloud with the free Wolfram Player or other Wolfram Language products.

Jack and Jill's parents ask them how they would like to get their allowance.


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?


Contributed by: Rob Morris (March 2011)
Open content licensed under CC BY-NC-SA




Feedback (field required)
Email (field required) Name
Occupation Organization
Note: Your message & contact information may be shared with the author of any specific Demonstration for which you give feedback.