I'm doing a basic question that specifies there are $p$ black balls, $q$ white balls, and $r$ red balls in an urn. You draw $n$ balls without replacement. I'm looking for the joint distribution of the number of black, white and red balls in the sample.
Since there are three variables I'm really confused about this. I'm not totally sure how to approach it, and I can't picture how you would even express this in a table or in another way. Any help is appreciated.
