Lattice Points for Endpoints and Midpoints
Source: 2006 SMT Advanced Topics Test Problem 7
March 20, 2010
analytic geometry
Problem Statement
A lattice point in the plane is a point whose coordinates are both integers. Given a set of 100 distinct lattice points in the plane, find the smallest number of line segments for which and are distinct lattice points in this set and the midpoint of is also a lattice point (not necessarily in the set).