How do I figure out how to solve a problem when I think I know to solve it?

[WalkingRadiance]

I think that the multivariate Wallenius hypergeometric or multivariate Fisher hypergeometric distribution is the key to a problem, but I'm not sure how to apply it. Mathematica has a function I could use to solve the problem, but I'm unsure how.
I am looking for suggestions on how to apply these distributions to combinatorics problems.
Please comment with a book recommendation with a step-by-step example.

Thank you

[pri_gua]

Just checking ... is this spam? In case it is not spam, this is not the place for this thread, it could be moved to 'Applied Mathematics' section below ... This thread would be better at https://math.stackexchange.com/ ...