Consider a disk with $256$ cylinders, indexed from $0$ to $255,$ with $0$ being the innermost and $255$ being

the outermost cylinder. The system receives disk requests on the following tracks in the specified order

$631765219484854746823027$

The head is currently on cylinder $82,$ and is moving towards outer cylinder. The head requires a total of $16$ms

to move from innermost to outermost track. Give the time required to service the given requests using each of

the following algorithms.

$($a$)$ FCFS scheduling

$($b$)$ SSTF scheduling

$($c$)$ SCAN scheduling

$($d$)$ C$-$SCAN scheduling, servicing requests as head moves outwards