Question

Can anyone help me wit this problem..

Twelve wrestlers compete in a competition. If each wrestler wrestles one match with each other wrestler, what is the total number of matches

Answer 1

Use formula for the number of combinations
`\\C_k^n= (n!)/((n-k)!k!) \\ \\n=12, k=2 \\ C_2^(12)= (12!)/((12-2)!2!)= (12!)/(10!2!)= (12*11)/(2*1)=66`