Which of the following is used to know the average number of customers in the Queue system when arrival rate is denoted by γ and service rate by μ?
1
\(\rm \frac{\lambda}{\mu}\)
2
\(\rm \frac{1}{\mu-\lambda}\)
3
\(\rm \frac{\lambda}{\mu (\mu-\lambda)}\)
4
\(\rm \frac{\lambda}{ (\mu-\lambda)}\)