In a room there are 9 people. Each person shook hands with every other person. How many hand shakes were there?  Options:
A) 36
B) 40
C) 44
D) 48
E) 52
9C2 = 36   The answer is 36.
<result>A</result>
In a room there are 9 people. Each person shook hands with every other person. How many hand shakes were there?