A computer processes jobs on a first-come, first-serve basis in a time-sharing environment.How fast does the computer have to process jobs, on average, to meet this objective?

A computer processes jobs on a first-come, first-serve basis in a time-sharing environment.How fast does the computer have to process jobs, on average, to meet this objective?
 . The jobs have Poisson arrival rates, with an average of six minutes between arrivals. The objective in processing these jobs is that they spend no more than eight minutes, on average, in the system. How fast does the computer have to process jobs, on average, to meet this objective?