Restaurant brand Happy Spice Hot Pot $($HSHP$)$ has started its online delivery business. The restaurant brand has $5$ physical dining locations in the bay area, and all the online orders are processed by these $5$ dining locations. The interarrival time of online order is $10$ mins on average, with a standard deviation of $5$ mins. Assume that the time to prepare and deliver the food is $30$ mins on average, with a standard deviation of $10$ mins. Use this information to answer the following four questions. $($Hint: the number of servers m is not $1.)$