MathDB
999 points in the plane

Source: Moldova JTST 2024 P3

June 10, 2024
combinatorial geometry

Problem Statement

Let MM be a set of 999 points in the plane with the property: For any 3 distinct points in MM we can choose two of them, such that the distance between them is less than 11. a)Prove that there exists a disc of radius not greater than 1 that covers at least 500 points in MM. b)Is it true that there always exists a disc of radius not greater than 1 that covers at least 501 points in MM?