MathDB
IMO ShortList 2002, combinatorics problem 5

Source: IMO ShortList 2002, combinatorics problem 5

September 28, 2004
combinatoricsIMO ShortlistSet systems

Problem Statement

Let r≥2r\geq2 be a fixed positive integer, and let FF be an infinite family of sets, each of size rr, no two of which are disjoint. Prove that there exists a set of size r−1r-1 that meets each set in FF.
Back to ProblemsView on AoPS