1979 USAMO Problems/Problem 5
Revision as of 20:17, 16 August 2011 by Mrdavid445 (talk | contribs) (Created page with "==Problem== Let <math>A_1,A_2,...,A_{n+1}</math> be distinct subsets of <math>[n]</math> with <math>|A_1|=|A_2|=\cdots =|A_n|=3</math>. Prove that <math>|A_i\cap A_j|=1</math> ...")
Problem
Let be distinct subsets of
with
. Prove that
for some pair