There are white balls and black balls in the bag , from which you can pick any two at a time.
(1) Find the probability that the two balls obtained are of different colors. (2) Find the probability that one of the two balls obtained is black.
Solution: This problem is a classical concept problem, which is solved by using the properties and combination of probability .
(1) Suppose event The two balls obtained by have different colors , then
.
(2) Suppose event
takes black ball ,
Get the black ball ,
Then and are mutually exclusive . Due to the limited additivity of probability and the combination formula , we have
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