n a G$/$G$/1$ queue, the average arrival rate is $10$ customers per hour and the standard

deviation of inter$-$arrival times is $12$ minutes. The service time is $3$ minutes per customer

and its standard deviation is zero. The average queue length is:

$($Hint: $)$

A$.1/3$ B$.1/2$ C$.1$ D$.2$

E$.$ None of the above