Let's say I have an urn with $n$ balls, with $K$ different colors of balls, where each color has the same number of balls: $\frac{n}{K}$. Given I reach into the urn and grab a ball (without replacement) $m$ times, what is the probability of getting $k$ different colors of balls?
I asked the same question here, and has one person commenting on it. I am wondering if anyone on this forum has additional useful insight.