2004 AIME I Problems/Problem 6

Revision as of 16:04, 12 October 2006 by JBL (talk | contribs)

Problem

An integer is called snakelike if its decimal representation $a_1a_2a_3\cdots a_k$ satisfies $a_i<a_{i+1}$ if $i$ is odd and $a_i>a_{i+1}$ if $i$ is even. How many snakelike integers between 1000 and 9999 have four distinct digits?

Solution

This problem needs a solution. If you have a solution for it, please help us out by adding it.

See also