6 people meet for a ceremony. Each person shakes hands once with each other person present. How many handshakes take place? Options:	A) 30	B) 21	C) 18	D) 15	E) 10
Let's look at the logic.   Every person shakes hand with other '5'. So, 6 people shake hands with 6X5= 30 people   But in this 30 we have counted two times the total handshakes (s shakes hand with t and t shakes hand with s)   So just divide 30/2= 
<gadget id="calculator">30/2</gadget>
<output>15</output>
15 total handshakes   Answer is 15
<result>D</result>
6 people meet for a ceremony. Each person shakes hands once with each other person present. How many handshakes take place?