MathDB
Minimum value of the number of points in the set M

Source: Chinese MO 2004

September 25, 2011
combinatorics proposedcombinatorics

Problem Statement

Let MM be a set consisting of nn points in the plane, satisfying: i) there exist 77 points in MM which constitute the vertices of a convex heptagon; ii) if for any 55 points in MM which constitute the vertices of a convex pentagon, then there is a point in MM which lies in the interior of the pentagon. Find the minimum value of nn.
Leng Gangsong
Back to ProblemsView on AoPS