Hi, Guess this should be easy, but could do with a pointer. Show directly that the set of probabilities associated with the hypergeometric distribution sum to 1. Hint: Expand the identity

So, how do you get from this to

which I take to be the formal statement of the verbal statement above, right? (i.e. the set of probabilities associated with the hypergeometric distribution sum to 1 (for a given r, w and N and where r + w = n)).

As always, much appreciated and thanks in advance for any insights.

Ta, MD