Answer :
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:
[tex]s = \dfrac{60}{12}[/tex]
s = 5 customers/ hour
Thus, the required average time for a customer needs to wait in line is:
[tex]= \dfrac{3}{5}\times (5-3) hours \\ \\ = \dfrac{3}{5}\times 2 \\ \\ = \dfrac{3}{10} \ hours[/tex]
To minutes;
[tex]= 3 \times \dfrac{60}{10} \ minutes[/tex]
= 18 minutes