In a room there are 12 people. Each person shook hands with every other person. How many hand shakes were there? Choose the correct choice.
A) 58  B) 60  C) 62  D) 64  E) 66
12C2 = 66   The answer is 66.
<result>E</result>
In a room there are 12 people. Each person shook hands with every other person. How many hand shakes were there?