Question
An urn contains 5 red and 2 black balls. Two balls are randomly drawn. Let X represent the number of black balls. What are the possible values of X ? Is X a random variable?
Solution
Number of red balls = 5
Number of black balls = 2
These two balls may be selected as RR, RB, BR, BB, where R represents red and B represents black ball.
Variable X has the value 0, 1, 2 i.e., there may be no black balls, may be one black ball, or both the balls are black.
Yes, X is a random variable.
