hi,

I think in general you can have a formula thta would look like this: assuming we have w white balls and N balls in total ( that is N-w blacks, the probability of winning at the first draw will be P(1)= w/N .

P(2) will be ((N-w)/N )*w/(N-1)

P(3) will be ((N-w)/N)*((N-w-1)/(N-1))*w/(N-2) and so on.

Interestingly if w=1 you can simplify the products and you get P(k) = 1/N for all k.

regards

rogojel