A pump has a useful life failure rate of 100 failures per 106 hours, a mean
wearout life of 10000 hr with a standard deviation of 2000 hr. Assuming
that the wearout failure distribution is normal, evaluate the reliability of
the pump for (a) a 100 hr mission starting at the 9900 hour point of its life
cycle and, (b) a similar mission starting 1000 hours later.