A computer printer in a large administrative office has a printer buffer $($memory to store printing jobs$)$ capacity of $3$ jobs. If the buffer is full when a user wants to print a file, the user is told that the job cannot be printed and to try again later. There are so many users in this office that it can be assumed that there is an infinite calling population. Jobs arrive at the printer at a Poisson rate of $55$ jobs per hour and take an average of $1$ minute to print. Printing times are exponentially distributed.