999 points in the plane
Source: Moldova JTST 2024 P3
June 10, 2024
combinatorial geometry
Problem Statement
Let be a set of 999 points in the plane with the property: For any 3 distinct points in we can choose two of them, such that the distance between them is less than .
a)Prove that there exists a disc of radius not greater than 1 that covers at least 500 points in .
b)Is it true that there always exists a disc of radius not greater than 1 that covers at least 501 points in ?