Dave,

I may be incorrect but my recollection of probability math indicated that the formula for number of possible combinations of 10 items taken 3 at a time without repeating is

10 * 9 * 8 or 720.

This represents the fact that position one can be any one of 10 possible items, positiom can be any one of 9 (since 1 of the 10 is in pos 1) and finally pos 3 can be any one of 8 (since 2 of them are in pos 1 and 2).

Am I incorrect, could you explain your formula?