20 chess players take part in a tournament. Every player plays twice with each of his opponents. How many games are to be played?  Choose the correct choice from the following answers: A) 380 B) 470 C) 560 D) 650 E) 740
2*20C2 = 2*190= 
<gadget id="calculator">2*190</gadget>
<output>380</output>
380   The answer is 380.
<result>A</result>
20 chess players take part in a tournament. Every player plays twice with each of his opponents. How many games are to be played?