Hi everybody,
Suppose that I have a list {1,2,3,4,5,6,7,8,9,10}.
A problem can be defined as "How many different ways to choose 5 disjoint pairs of items from 10 items"
I know that the number of these sets is 9!!=9x7x5x3x1.
For example {1,2},{3,4},{5,6},{7,8},{9,10} and {1,3},{2,4},{5,6},{7,8},{9,10} are such sets and of course {1,2},{3,4},{5,6},{7,8},{9,10} ={2,1},{3,4},{5,6},{7,8},{9,10}.
My question is how can I create and export these sets in Mathematica. Is there any built in function or programming is needed?.
Thanks in advance
