At the end of a business conference the 20 people present all shake hands with each other once. How many handshakes will there be altogether ? Select.
A) 20  B) 45  C) 55  D) 190  E) 95
number of handshakes = 20C2= 20*19/2= 
<gadget id="calculator">20*19/2</gadget>
<output>190</output>
190   ANSWER:190
<result>D</result>
At the end of a business conference the 20 people present all shake hands with each other once. How many handshakes will there be altogether ?