Two factories I and II produce phones for brand ABC. Factory I produces 60% of all ABC phones and Factory II produces 40%. 10% of the phones from Factory I are defective, and 20% of those produced by factory II are defective. You purchase a brand ABC phone, and assume the phone is randomly chosen from all ABC phones. Suppose the phone is defective.

a) Compute the probability that the phone came from Factory II, given that the phone is defective, P(F actory II|defective).