MathDB
Iran National Math Olympiad-Day 1-Problem 2

Source:

April 30, 2010
geometrycombinatoricscounting question

Problem Statement

There are nn points in the page such that no three of them are collinear.Prove that number of triangles that vertices of them are chosen from these nn points and area of them is 1,is not greater than 23(n2−n)\frac23(n^2-n).
Back to ProblemsView on AoPS