If 15 people attend a conference and each person shakes hands with every other person exactly once, find the total number of handshakes.

Question: If 15 people attend a conference and each person shakes hands with every other person exactly once, find the total number of handshakes.Solution:Total handshakes = 15C2 = 15!/2!(15 - 2)!= (15 × 14 × 13!)/(2 × 13!)= 105Thus, the total number of handshakes is 105.