Customers arrive at a bakery at an average rate of 18 per hour. There are 2 servers, and each serve a customer in an average of four minutes.

Customers arrive at a bakery at an average rate of 18 per hour. There are 2 servers, and each serve a customer in an average of four minutes. Assuming Poisson arrivals and Exponential service time, what is the average number of customers being served at any time?

a.    0.6

b.   1.2

c.     2.4

d.    2

None of the above