The circumference of Earth is 24,901 miles
Answer:
18 minutes
Step-by-step explanation:
Given that:
The arrival time = 3 customers / hour
The avg. service rate (s) = 12 minutes per customer
To hour, we have:

s = 5 customers/ hour
Thus, the required average time for a customer needs to wait in line is:

To minutes;

= 18 minutes
Z-m=z+bx
z-m-z=z+bx-z
-m=bx
bx=-m
bx/b=-m/b; b=0
x=-m/b; b=0
I would say B but I can't see the question very well.