MathDB
Colouring the nk objects k different colours

Source: Baltic Way 1998

January 11, 2011
combinatorics proposedcombinatorics

Problem Statement

Let nn and kk be positive integers. There are nknk objects (of the same size) and kk boxes, each of which can hold nn objects. Each object is coloured in one of kk different colours. Show that the objects can be packed in the boxes so that each box holds objects of at most two colours.