Answer to July 2007 Problem
Manhattan & the Indians

David Letterman mentioned the following on his show in February, 2007:
"In 1626, we bought Manhattan from the Indians for $24.
Today, it would be worth 730 trillion dollars."

At what interest rate would you have to invest $24 in 1626 so that it would be worth $730 trillion in 2007?
Assume that the rate stays constant and that it is compounded annually.
Give your answer as a percent correct to two decimal places (e.g., like 3.74%).

 

Solution to the Problem:

The answer is 8.49%.


Many thanks to Evelyne Stalzer for correcting my spelling of Manhattan!

Correctly solved by:

1. David and Judy Dixon Bennettsville, South Carolina
2. Richard K. Johnson La Jolla, California
3. K. Sengupta Calcutta, INDIA
4. Evelyne Stalzer Montville, New Jersey
5. Magdy Essafty Alexandria, Egypt
6. Tristan Collins Virginia Tech
Blacksburg, Virginia
7. Tom Robb John Handley High School
Winchester, Virginia