Sum of circumferences is 10 => Line intersects 4 disks
Source: German DEMO 2008, grade 11-13, round 4, problem 5
May 22, 2008
combinatorics proposedcombinatorics
Problem Statement
Inside a square of sidelength there are finitely many disks that are allowed to overlap. The sum of all circumferences is . Show that there is a line intersecting or touching at least disks.