A Small Popular Restaurant at an Interstate Truck Stop Provides

Multiple Choice

A small popular restaurant at an interstate truck stop provides priority service to truckers.The restaurant has ten tables where customers may be seated.The service time averages 40 minutes once a party is seated.The customer arrival rate is 12 parties per hour,with the parties being equally divided between truckers and non-truckers.
-What is the approximate average time in minutes that non-truckers wait to be seated?

A) 2 7
B) 4 5
C) 8 4
D) 13 6
E) 15 8