1. Prove the multinomial criterion (formula 3.55). Assume that L has density Fl
2. A system is maintained according to policy 7 (section 220.127.116.11). The repair cost of a system failing at time t has a uniform distribution over the interval [a, a + bt] with and a ≥ 0 b > 0.
3. Under the same assumptions as in section 18.104.22.168 (in particular assumptions (3.96) and (3.99)), show that every linearly increasing repair cost limit c(t) = c + dt with and a leads to a higher maintenance cost rate than given by (3.105).