An emergency backup generator experiences standby (dormant) failures at a constant rate of 0.00314..

An emergency backup generator experiences standby (dormant)
failures at a constant rate of 0.00314 per day. It takes 6 hr to inspect and
test the generator. If it is found to be inoperative, it takes 24 hr to repair
it. Determine an inspection interval that will maximize the availability of the
generator.