What is the average number of customers in a system $($Ls$)$ for an M$/$M$/1$ queue model with $\backslash$lambda $=7$ customers$/$hour and $\backslash$mu $=10$ customers$/$hour$?$

Question $13$ options:

$0\mathrm{.}7$

$1\mathrm{.}4$

$2\mathrm{.}3$

$3\mathrm{.}5$

None of the above