7 chess players take part in a tournament. Every player plays twice with each of his opponents. How many games are to be played? Pick:
A) 40
B) 48
C) 45
D) 42
E) 22

Rationale: "though 2 * ( 7 c 2 ) is the correct approcah to do this , but for people like me who find perm , comb n prob a nightmare , an easy approach can be used . the first guy has to play 2 matches with the rest of 6 , so he ' ll play 12 matches . similarly , second guy has to play with the rest of 5 as his 2 games with the first guy are already played . so he plays 10 matches . this continues like this and the total matches are 12 + 10 + 8 . . . + 2 12 + 10 + . . . + 2 = 2 ( 6 + 5 + . . . + 1 ) = 2 ( ( 6 * 7 ) / 2 ) = 6 * 7 = 42 . answer : d"
Answer: D