*Consider n multinomial trials, where each trial independently results in outcome i with probability . With equal to the number of trials that result in outcome i, find *
I'm having a hard time understanding what the question is asking. Am I looking for the average number of trials that result in

given that there's at least one trial that results in

?

To work out the conditional expectation you need the conditional probability:

EDIT:

After thinking about it, isn't the answer just

I don't know, I don't think I'm getting the question.