I'm worse than an earthworm when it comes to math (they know how to divide i hear...) so if y'all could help me out with this problem that would be great. Or at least point me in the right direction.

In a given set there are 20 unique items

How many combinations of exactly 4 of these items can be generated?

The relative positions of each of the elements DOES matter.

IOW: The sets (2, 18, 10, 4) and (18, 4, 2, 10) are fundamentally different for my purposes.

Anyway, I don't expect someone else to do the work for me (though if you would like that would be great..) so if anyone can just give me a formula or point me somewhere to find one.

Thanks

Thanks guys. That was much more simple than I was thinking it was going to be with a smaller number than I had thought.

It's still friggin huge when dealing with cards...