4. The first bag contains 4 red chips and 5 blue chips. The second bag contains 7 red chips and 2 blue chips. Two chips are drawn at random, the first from bag 1 and the second from bag 2. a] Find the probability that the chips are of the same colour. /2 b] Given that the chips are of different colours, find the probability that the red chip was selected from bag 1. /4