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ENgez
Mar17-11, 02:21 PM
1. The problem statement, all variables and given/known data
you have a sack with 5 red balls, 5 black balls and 5 white balls. you take them out one at a time without returning until the sack is empty. what is the probability the last ball you took out is red given that the first ball taken out is not white.



2. Relevant equations
it should be solvable using the bayes theorom, the definition of conditioned probabilty, and the complete probability formula.



3. The attempt at a solution
i tried playing around with different events and using the formulas above but no luck... the main problem is that the probability tree is huge. i was hoping i can get a push in the right direction.

thanks.

tiny-tim
Mar17-11, 05:02 PM
Hi ENgez! :smile:

You have a sack with 5 red balls, 4 black balls and 5 white balls. You take them out one at a time without returning until the sack is empty. what is the probability the last ball you took out is red? :wink: