Question

Suppose that Bob can decide to go to work by one of the three modes of transportation; car, bus, or train. Because of high traffic, if he decides to go by car, there is a 50% chance he will be late. If he goes by bus there is a 20% chance he will be late. If he goes by train there is only 1% chance that he will be late. Suppose he takes the car 10% of the time, the bus 1% of the time, and the train 89% of the time, What is the probability that Bob will be late getting to work?

Answer 1

The probability is (0.10 * 0.50 + 0.01 * 0.20 + 0.89 * 0.01) * 100% = 6.09%.