7.3 Exercise 10

For the system in the exercise, call a day in which one or more failures occur among the 350 lamps a “service day.” Since a Bernoulli sequence “starts over” at any time, the sequence of service/nonservice days may be considered a Bernoulli sequence with probability p₁, the probability of one or more lamp failures in a day.

1. Beginning on a Monday morning, what is the probability the first service day is the first, second, third, fourth, fifth day of the week?
2. What is the probability of no service days in a seven day week?