MathDB
TOT 540 1997 Spring S O5 red and green points

Source:

September 11, 2024
combinatoricsColoringcombinatorial geometry

Problem Statement

In a game, the first player paints a point on the plane red; the second player paints 10 uncoloured points on the plane green; then the first player paints an uncoloured point on the plane red; the second player paints 10 uncoloured points on the plane green; and so on. The first player wins if there are three red points which form an equilateral triangle. Can the second player prevent the first player from winning?
(A Kanel)