October 30–November 5, 2007
Problem
A number (in decimal) can be transformed in the following three ways:
- Append a '4' on the end of the number; for example, 135 -->1354
- Append a '0' to the end
- If the number is even, divide by two.
Start with the number '4'. Prove that for any natural number n, there is a sequence of the above operations to get to n.
Solution
here.
List of solvers
Aaron Dilley (undergraduate); Dustin Moody, Adam Estrup, (graduate); Gary Raymond (faculty); Rich Bauer (alum)
Dustin Moody wins the prize!