Three production lines contribute to the total pool of a company's product. Line 1 provides 20% to the pool and 10% of its products are defective; Line 2 provides 50% to the pool and 5% of its products are defective; Line 3 contributes 30% to the pool and 6% of its products are defective.
(a) What percent of the items in the pool are defective?
(b) Suppose an item is randomly selected from the pool and found to be defective. What is the probability that it came from Line 1?