MathDB

3

Part of 1986 Austrian-Polish Competition

Problems(1)

exists a unit square having exactly 0,1 or 4 blue vertices

Source: Austrian Polish 1986 APMC

4/30/2020
Each point in space is colored either blue or red. Show that there exists a unit square having exactly 0,10, 1 or 44 blue vertices.
Coloringsquarecombinatorics