Packages arrive at a facility at a rate of 30 per hour and are processed continuously at a rate of 25 per hour. The facility is open from 8 a. m. to 4 p. m. How long does the last package wait before it is processed?

1.6 hour

Explanation:

Given

Rate of Arrival = 30 per hour

Rate of Processing = 25 per hour

Open Time = 8am

Close Time = 4pm

How long the last package has to wait before it is processed is calculated by;

Duration = ∆Time/∆Rate

∆Time = 4pm - 8am

∆Time = 8 hours

∆Rate = Rate of Arrival - Rate of Processing

∆Rate = 30 - 25

∆Rate = 5 per hour

Duration = 8 hours : 5 per hour

Duration = 1.6 hours