Question

One bag contains 5 white and 3 black balls. Another bag contains 4 white and 6 black balls. If one ball is drawn from each bag, find the probability that 

(i) both are white 

(ii) both are black 

(iii) one white and one black

Answer 1

Bag	White Balls	Black Balls	Total
I	5	3	8
II	4	6	10

P(WW) = P(W) P(W) 

P(White from bag I) = 5/8

P(White from bag II) = 4/10

P(Black from bag I) = 3/8

P(Black from bag II) = 6/10

(i) P(WW) = P(W) P(W) = (5/8) x (4/10) = 20/80 = 1/4

(ii) P(BB) = P(B) P(B) = (3/8) x (6/10) = 18/80 = 9/40

(iii)