10 people meet and shake hands. The maximum number of handshakes possible if there is to be no cycle of handshakes is (A cycle of handshakes is a sequence of k people a1, a2, ......, ak (k > 2) such that the pairs {a1, a2}, {a2, a3}, ......, {ak-1, ak}, {ak, a1} shake hands).
10 people meet and shake hands. The maximum number of handshakes possible if there is to be no cycle of handshakes is (A cycle of handshakes is a sequence of k people a1, a2, ......, ak (k > 2) such that the pairs {a1, a2}, {a2, a3}, ......, {ak-1, ak}, {ak, a1} shake hands).










