Everyone shakes hands with everyone else in a room. Total number of handshakes is 120. Number of persons=? Answers:
A) a.14 B) b.12 C) c.11 D) d.15 E) e.16
In a room of n people, the number of possible handshakes is C(n,2) or n(n-1)/2   So n(n-1)/2 = 120 OR n(n-1)=240 OR n=16   Answer is (e.16)
<result>E</result>
Everyone shakes hands with everyone else in a room. Total number of handshakes is 120. Number of persons=?