1. Netflix is concerned that some subscribers holding on to new releases too long. Netflix wants to send a reminder to 10% of its subscribers who still hold new DVDs too long before they send back. Netflix believes that such a reminder will speed up circulation of new DVDs and will enable Netflix to provide the same level of service with fewer copies. How many days should Netflix wait (from the time at which the DVD is mailed from the warehouse) before sending out the reminder?

Hint: Netflix wants to send messages to customers who still have the DVDs at their home. Should you use the total rent cycle time (