A box contains 4 black, 2 white and 6 red balls. Another box contains 3 black and 5 white balls. Throwing an…
A box contains 4 black, 2 white and 6 red balls. Another box contains 3 black and 5 white balls. Throwing an unbiassed die, a ball is drawn from the first box if either 1 or 2 appears on the die-otherwise a ball is drawn from the second box. If the drawn ball is black then the probability that 2 appeared on the die is