6 wrestlers compete in a competition. if each wrestler wrestles one match with each other wrestler, what are the total numbers of matches?

The total number of wrestlers are 6 and each have to wrestle each other wrestler only once.

It means, the first wrestler have 5 opponent, second have 4 opponents, third have three oponenets, fourth have two opponents and the fifth have only one opponent.

So the total number of matches = 5+4+3+2+1 = 15

5 wrestling matches