two monochromatic triangles, given 7 points
Source: Bulgaria 1985 P4
June 16, 2021
graph theorycombinatorics
Problem Statement
Seven points are given in space, no four of which are on a plane. Each of the segments with the endpoints in these points is painted black or red. Prove that there are two monochromatic triangles (not necessarily both of the same color) with no common edge. Does the statement hold for six points?