At 8:00 A.M. there are 10 vehicles in a queue at a toll booth and vehicles are arriving at a rate of λ(t) = 6.9 - 0.2t. Beginning at 8 A.M., vehicles are being serviced at a rate of µ(t) = 2.1 + 0.3t (µ(t) and µ(t) are in vehicles per minute and t is in minutes after 8:00 A.M.).
Assuming D/D/1 queuing, what is the maximum queue length, and what would the total delay be from 8:00 A.M. until the queue clears?