The urn contains 2 white and 2 black balls.A ball is drawn at random.If it is white,it is not replaced into urn.Otherwise,it is replaced with another ball of the same colour.The process is repeated.Find probability that third ball drawn is black
The urn contains 2 white and 2 black balls.A ball is drawn at random.If it is white,it is not replaced into urn.Otherwise,it is replaced with another ball of the same colour.The process is repeated.Find probability that third ball drawn is black