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Question
An urn contains 5 red and 2 black balls. Two balls are drawn at random. X denotes number of black balls drawn. What are possible values of X?
Solution 1
The urn contains 5 red and 2 black balls. If two balls are drawn from the urn, it contains either 0 or 1 or 2 black balls.
X can take values 0, 1, 2.
∴ X = {0, 1, 2}.
Solution 2
X denotes the number of black balls drawn.
Sample space of the experiment is
S = {RR, BR, RB, BB}
The value of X corresponding to these outcomes are as follows:
X (RR) = 0
X(BR) = X(RB) = 1
X(BB) = 2
∴ Possible values of X are {0, 1, 2}.
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