Bag contains 2 white,1 black and 3 red balls,Bag B contains 3 white ,2 black and 4 red balls and Bag C contains 4 white ,3 black and 2 red balls.One Bag is chosen at random and 2 balls are drawn at random from that Bag.If the randomly drawn balls happen to be red and black,what is the probability that both balls come from Bag B?