Question 23
How many ways are there to choose three pairs of players for doubles from $n\ge6$ players?
Choose six distinct players and split them into three unlabelled pairs. A player may occur in only one pair; the order within each pair and the order of the pairs do not count.
Choose six distinct players and split them into three unlabelled pairs. A player may occur in only one pair; the order within each pair and the order of the pairs do not count.