IMO Shortlist 2011, Combinatorics 2
Source: IMO Shortlist 2011, Combinatorics 2
July 12, 2012
combinatoricsIMO ShortlistHi
Problem Statement
Suppose that students are standing in a circle. Prove that there exists an integer with such that in this circle there exists a contiguous group of students, for which the first half contains the same number of girls as the second half.Proposed by Gerhard Wöginger, Austria