1. A light-bulb manufacturer knows that .05% of all bulbs manufactured are defective. A testing machine is 99% effective; that is, 99% of good bulbs will be declared fine and 99% of flawed bulbs will be declared defective. If a randomly selected light-bulb is tested and found to be defective, what is the probability that it actually is defective?
2. Urn I contains 5 red balls and 5 white balls. Urn II contains 12 white balls. A ball is selected at random from urn I and placed in urn II. Then a ball is selected at random from urn II. What is the probability that the second ball is white?