Question

An urn contains 4 white and 6 red balls. Four balls are drawn at random from the urn. Find the probability of the number of white balls.

Answer 1

Let X represents white balls. 

∴ Total balls =4 + 6 = 10 

Four balls are drawn at random. 

∴ Expected values of X will be 0,1,2,3,4. 

∴ P(X = 0) = P(all red) 

= P(RRRR)

∴ Required probability distrubution is following: