MathDB
IMO Shortlist 2014 C1

Source:

July 11, 2015
IMO Shortlistnumber theory

Problem Statement

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