A supplier purchases 20% of its parts from the factory A, 70% of its parts from the factory B, and the remainder from the factory C. Seven percent of A's parts are defective, 5% of B's parts are defective, and 8% of C's parts are defective.

(a)What is the probability that the selected defective part was produced in the factory C ?

(b)What is the probability that the selected defective part was not produced in the factory A ?