2005 AIME II Problems/Problem 5
Revision as of 11:24, 5 July 2006 by Ragnarok23 (talk | contribs)
Problem
Robert has 4 indistinguishable gold coins and 4 indistinguishable silver coins. Each coin has an engraving of one face on one side, but not on the other. He wants to stack the eight coins on a table into a single stack so that no two adjacent coins are face to face. Find the number of possible distunguishable arrangements of the 8 coins.