Pickmeup Is a Drive Through Coffee House That Has Room

Multiple Choice

Pickmeup is a drive through coffee house that has room for 3 cars in the driveway. The line cannot exceed 3 cars, and because they are exclusively drive through, customers may be turned away. In the morning, the arrival rate is 40 cars per hour (Poisson distributed) and with the servers working in teams, they can process 50 cars per hour (the service rate is exponential) . What is the probability of turning customers away?

A) .173
B) .210
C) .339
D) .410