Blue points inside red triangles
Source: Kürschák 1991, problem 3
July 20, 2014
combinatorics unsolvedcombinatorics
Problem Statement
Consider red points on the plane with no three collinear. We select blue points in such a way that inside each triangle whose vertices are red points, there is a blue point as well. Find the smallest for which the described selection of blue points is possible for any configuration of red points.