Question

To avoid creeps from taking covert photos, iPhones bought in Japan (and seemingly also South Korea) cannot be muted when using the camera. The mandatory shutter sound was installed to reduce voyeuristic “up-skirt” photography - especially in crowded places like rush-hour trains. The chips responsible for the camera’s sound are produced at two manufacturing plants; one in Korea, and the other in Japan. The Korean factory makes 40% of the chips, while the Japanese plant produces the remaining 60%. Quality control has determined that 2% of the chips manufactured in Korea are defective, and 3% of the chips made in Japan are defective.

(a) If a randomly selected chip is found to be defective, what is the probability that it was manufactured in Korea?

(b) If a randomly selected chip is not defective, what is the probability that it was made in Japan?

(c) What is the probability that a randomly selected was made in Japan or not defective?

Answer 1