Pairs of students in same row and of same sex not greater 11
Source: CWMO 2003, Problem 8
December 27, 2008
inequalitiesfunctionvectorgraph theorycombinatorics unsolvedcombinatorics
Problem Statement
students are arranged in rows and columns. It is known that in any two columns, the number of pairs of students in the same row and of the same sex is not greater than . Prove that the number of boys is not greater than .