If each participant of a chess tournament plays exactly one game with each of the remaining participants, then 190 games will be played during the tournament. What is the number of participants?
Choose the correct choice from the following choices.
A) 14 B) 16 C) 18 D) 20 E) 22
Let n be the number of participants.   The number of games is nC2 = n*(n-1) / 2 = 190   n*(n-1) = 380 = 20*19 (trial and error)   The answer is 20.
<result>D</result>
If each participant of a chess tournament plays exactly one game with each of the remaining participants, then 190 games will be played during the tournament. What is the number of participants?