Re: Probability problem - couting number of distinct elements

rvelosoo@xxxxxxxxx wrote: 
Hi all, i have the following problem: suppose we have a bag with N
balls with different colors. Randomly, i take one ball from the bag,
record the color, and put it back in the bag. Now, the question is:
after taking k balls from the bag, what's the expected number of
different colors i have seen? Any suggestion? Thanks! --Ricardo

Deal with it in cases. Find the probability if finding k different colors, k-1 different colors, k-2 different colors, etc.
--
Will Twentyman
email: wtwentyman at copper dot net
.

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