SOLUTION: if 109 boys play a chess tournament, how many games have to be played so that each boy plays everyone

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Question 535019: if 109 boys play a chess tournament, how many games have to be played so that each boy plays everyone
Answer by htmentor(1343) About Me  (Show Source):
You can put this solution on YOUR website!
This is a combination problem in which 91 things are taken 2 at a time
So the number of games is
C(91,2) = 91!/(2!89!) = 91*90/2 = 4095