Problem of the Week 925

The Last Two Digits

What are the last two digits of (1+5^(2n+1))/6?

Note that n is assumed to be any positive integer.

Source: The current issue of Crux (Problem 2578).

NOTE: This is from the Problem Section of Crux. It is our hope that one of the Macalester Students will solve the problem and send in a solution by the deadline of April 1. We will not post a solution to the email list or on the web site until then.

© Copyright 2000 Stan Wagon. Reproduced with permission.

7 December 2000