If each participant of a chess tournament plays exactly one game with each of the remaining participants, then 253 games will be played during the tournament. What is the number of participants?	Options:
A) 21 B) 22 C) 23 D) 24 E) 25

Rationale: "let n be the number of participants . the number of games is nc 2 = n * ( n - 1 ) / 2 = 253 n * ( n - 1 ) = 506 = 23 * 22 ( trial and error ) the answer is c ."
Answer: C