22 people attend a party. Each person shakes hands with at most 20 other people. What is the maximum possible number of handshakes, assuming that any two people can shake hands at most once?
+23246 22 persons shaking hands with 20 persons (each) result in 22 x 20 = 440 handshakes.
However, this is double the actual amount since, when person A is shakomg hands with
person B, B is then (also) shaking hands with person A.
So, we need to divide the answer that we got by 2: 440 / 2 = 220 handshakes.
