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 ?

Answer 1

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 black balls.

Yes, X is a random variable.