MathDB
Partition with Product

Source: AIME 2010 Problem 12

March 17, 2010
AMCAIME

Problem Statement

Let M3 M \ge 3 be an integer and let S \equal{} \{3,4,5,\ldots,m\}. Find the smallest value of m m such that for every partition of S S into two subsets, at least one of the subsets contains integers a a, b b, and c c (not necessarily distinct) such that ab \equal{} c.
Note: a partition of S S is a pair of sets A A, B B such that A \cap B \equal{} \emptyset, A \cup B \equal{} S.