Covering any 3 points with 1-strip => cover all with 2-strip
Source: Balkan MO 2010, Problem 3
May 4, 2010
inductiongeometrytrigonometrycombinatorics proposedcombinatoricsExtremal combinatorics
Problem Statement
A strip of width is the set of all points which lie on, or between, two parallel lines distance apart. Let be a set of () points on the plane such that any three different points of can be covered by a strip of width .
Prove that can be covered by a strip of width .