If each participant of a chess tournament plays exactly one game with each of the remaining participants, then 105 games will be played during the tournament. Find the number of participants. Choose the correct option.
A) 15
B) 16
C) 17
D) 18
E) 19
Let P be the number of participants.   PC2 = 105   (P)(P-1) = 210 = 15*14   P = 15   The answer is 15.
<result>A</result>
If each participant of a chess tournament plays exactly one game with each of the remaining participants, then 105 games will be played during the tournament. Find the number of participants.