A retailer replenishes one of its products from four factories, A, B, C, and D: A provides 20% of the supply, B supplies 25%, C’s share is 32%, the rest comes from D. The percentages of defectives from the four factories are 1, 2, 1.5, and 2.8, respectively, includes 10% defective items, whereas factory is known to produce less defectives at 8%.

(a) What is the overall percentage of defectives from all four factories?

(b) What is the probability that a random defective item comes from Factory A? Factory B? Factory C? Factory D?