IMO 2014 Shortlist C1

Let n points be given inside a rectangle R such that no two of them lie on a line parallel to one of the sides of R. The...

IMO 2014 Shortlist C1

Category: Combinatorics

Problem

Let n points be given inside a rectangle R such that no two of them lie on a line parallel to one of the sides of R. The rectangle R is to be dissected into smaller rectangles with sides parallel to the sides of R in such a way that none of these rectangles contains any of the given points in its interior. Prove that we have to dissect R into at least n ` 1 smaller rectangles. (Serbia)