Bag A contains 4 white balls and 2 black balls. Bag B contains 2 white balls and 3 black balls. A ball is drawn at random from bag A and is put in bag B. Then a ball is drawn at random from bag B. What is the probability that the ball drawn is black?
P(black drawn at B)
= P(black from A, then black drawn at B) + P(white from A, then black drawn at B)
= (2/6) x (4/6) + (4/6) x (3/6)
= (8/36) + (12/36)
= 20/36
= 5/9
=