Suppose that a disk has $200$ cylinders, numbered $0$ to $199.$ the drive is currently serving a request at cylinder $50.$ The queue of pending requests, in FIFO order:

$100,185,35,125,15,125,65,69$

Starting from the current head position, show the total distance $($in cylinders$)$ that the disk arm moves to satisfy all the pending requests for each of the following disk$-$schedulin disciplines:

$($i$)$

$($ii$)$

$($iii$)$

FCES

SCAN

C$-$SCAN