MathDB
Chess, women versus men

Source: Problem 8, Brazil MO 1992

March 18, 2006
combinatorics proposedcombinatorics

Problem Statement

In a chess tournament each player plays every other player once. A player gets 1 point for a win, 0.5 point for a draw and 0 for a loss. Both men and women played in the tournament and each player scored the same total of points against women as against men. Show that the total number of players must be a square.