THIS MONTH'S QUIZ
If four chessplayers, A, B, C and D, are to engage in a tournament, there are just three ways in which they can be paired off for their first game, as shown below:
(i) AB,CD (ii) AC,BD (iii) AD,BC
1. In how many ways can six players be paired off?
2. In how many ways can eight players be paired off?
3. In how many ways can twenty players be paired off?
