6 people meet for a business lunch. Each person shakes hands once with each other person present. How many handshakes take place?	Pick: A) 30 B) 21 C) 18 D) 15 E) 10
the formula to count handshakes is n(n−1)2n(n−1)2   Where n is the number of people   =&gt; 6(6-1)/2 = 6*5/2 = 30/2= 
<gadget id="calculator">30/2</gadget>
<output>15</output>
15=&gt; the answer is 15(15)
<result>D</result>
6 people meet for a business lunch. Each person shakes hands once with each other person present. How many handshakes take place?