Assume that you have to pick a scheduling algorithm to run the following processes:

$$ P$1,$ which requires $1$ hour of CPU time to complete;

$$ P$2,$ which requires $2$ hours of CPU time to complete;

$$ P$3,$ which requires $1$ min of CPU time to complete;

Assume all processes are ready at the same time.

a$.$ Assume you use First Come First Serve $($FCFS$)$ to schedule these processes. Which is the schedule with the largest average completion time? Which is the schedule with the smallest average completion times? Compute the average completion time in each case.

b$.$ Assume you use Round$-$Robin with a time quanta $($slice$)$ of $100$ms$.$ What is the completion time of each job in this case? Assume that there is no context switch overhead.

c$.$ Now assume that P$1$ arrives at t$=0,$ P$2$ arrives at time t$=10$min, and P$3$ at time t$=20$min. What will be the completion time of each process when using the Preemptive Shortest Job First algorithm?