License Plates
Source: AIME II 2007 #1
March 29, 2007
AMCAIME
Problem Statement
A mathematical organization is producing a set of commemorative license plates. Each plate contains a sequence of five characters chosen from the four letters in AIME and the four digits in . No character may appear in a sequence more times than it appears among the four letters in AIME or the four digits in . A set of plates in which each possible sequence appears exactly once contains license plates. Find .