Cono Sur Olympiad 2005, Problem 6
Source:
August 19, 2014
symmetryanalytic geometrycombinatorics unsolvedcombinatorics
Problem Statement
On the cartesian plane we draw circunferences of radii 1/20 centred in each lattice point. Show that any circunference of radii 100 in the cartesian plane intersect at least one of the small circunferences.