At a party, everyone shook hands with everybody else. If there were 66 handshakes, how many people were at the party ?

At a party, everyone shook hands with everybody else. If there were 66 handshakes, how many people were at the party ?

A 9

B 15

C 10

D 12

Solution

Correct Answer: Option D

66\( \times \)2 = 12 then 12 = 12\( \times \)11 ans: 12