Question $8$

A restaurant kitchen is able to serve $20$ customers $$ hour and is open for dinner only from $5PM$ to $10PM.$ If on a Thursday night the restaurant serves $80$ customers $($i$.$e$.,$ between $5$ and $10$ PM a total of $80$ customers arrive, eat their meal and leave$),$ which statement below is the most valid?

This is a stable process because at the end of $5$ hours the number completed equals the number of customers that arrived.

This is a stable process because by design it has more capacity than demand.

This is NOT a stable process because the inflow rate equals the outflow rate.

This is NOT a stable process because the potential outflow rate is much greater than the inflow rate $($i$.$e$.,$ Ro $=100,$ while $Ri=80)$