IMO 1988 LL NET67
Given a set of 1988 points in the plane, no three points of the
IMO 1988 LL NET67
Origin: NET
Problem
Given a set of 1988 points in the plane, no three points of the set collinear, the points of a subset with 1788 points are colored blue, and the remaining 200 are colored red. Prove that there exists a line in the plane such that each of the two parts into which the line divides the plane contains 894 blue points and 100 red points.