Question $5$: CPU Scheduling

$[27]$

The following processes are being scheduled using a preemptive, priority$-$based, round$-$robin scheduling algorithm:

$\backslash$table$[[$Process$,$Priority,Burst,Arrival$],[$P$1,3,15,0],[$P$2,8,20,0],[$P$3,5,20,20],[$P$4,5,20,25],[$P$5,4,5,45],[$P$6,4,15,55]]$

Each process is assigned a numerical priority, with a higher number indicating a higher relative priority. The scheduler will execute the highest$-$priority process. For processes with the same priority, a round$-$robin scheduler will be used with a time quantum of $10$ units. If a process is preempted by a higher$-$priority process, the preempted process is placed at the end of queue.

a$.$ Show the scheduling order of the processes using a Gantt chart.

$(6)$

b$.$ What is the turnaround time of each process?

$(4)$

c$.$ What is the waiting time of each process?

$(4)$