Question

An urn contains 4 white and 3 red bails. Find the probability distribution of the number of red balls if 3 balls are drawn at random.

Answer 1

Three balls are taken out of an urn 

∴ Sample space is 

= S{RRR, RRW, RWR, WRR, RWW WRW, WWR WWW} 

Where R respresents red ball and W, white ball.

Let X = number of red balls. 

So possible value of X are 3,2,1,2,1,0 or 0, 1,2, 3 (No red ball)