Eight members of a chess club are having a tournament. In the first round every player will play a chess game against every other player. How many games will be in the first tournament
Same as handshake problem. Each of n persons plays against n-1 persons for a total of n(n-1)/2 games. The division by 2 is necessary to avoid double counting the game A vs B and B vs A.
For n=8, then number of games played in the first round is 8(8-1)/2=28 games.
