3 Consider the following queuing systems:

System 1 An average of 40 customers arrive each hour;

interarrival times are exponential. Customers must complete two types of service before leaving the system. The first server takes an average of 30 seconds (exponentially distributed) to perform type 1 service. After waiting in line, each customer obtains type 2 service (exponentially distributed with a mean of 1 minute) from a single server. After completing type 2 service, a customer leaves the system.

System 2 The arrival process for system 2 is identical to the interarrival process for system 1. In system 2, a customer must complete only one type of service. Service time averages 1.5 minutes and is exponentially distributed. Two servers are available.

In which system does a typical customer spend less time?