1. A machine produces 12,000 bolts per day, with a 3% defect rate. What is the probability that twelve defective bolts will be found in a sample of 600 bolts?
2. One bag contains 4 white balls and 2 black balls. A second bag contains 3 white balls and 5 black balls. One of the two bags is chosen at random, and a ball selected randomly. The ball is white. What is the chance the bag selected was the first bag?