MathDB
Chessboard

Source:

January 25, 2005
graph theorycombinatorics unsolvedcombinatorics

Problem Statement

In the unit squre For the given natural number n2n \geq 2 find the smallest number kk that from each set of kk unit squares of the nnxnn chessboard one can achoose a subset such that the number of the unit squares contained in this subset an lying in a row or column of the chessboard is even