China TST 1986 4k circle markers
Source: China TST 1986, problem 8
May 16, 2005
combinatorics unsolvedcombinatoricspointsChordsChinaTSTTeam Selection Test
Problem Statement
Mark points in a circle and number them arbitrarily with numbers from to . The chords cannot share common endpoints, also, the endpoints of these chords should be among the points. i. Prove that pairwisely non-intersecting chords can be drawn for each of whom its endpoints differ in at most .
ii. Prove that the cannot be improved.