A computer manufacturer uses chips from three sources. Chips from sources A, B, and C are defective with probabilities 0.005, 0.001, and 0.010, respectively. You can assume that the proportions of chips from A, B and C are 0.5, 0.1, and 0.4 respectively. If a randomly selected chip is found to be defective, find the probability that the manufacturer was A and the probability that the manufacturer was C.