Disk requests come into the disk driver for cylinders 40, 10, 20, 22, 42, 8, 2 and 29, in

that order. A seek takes 5 msec per cylinder moved. Assuming the disk arm is initially at

cylinder 25, compute the total seek time for each of the following:

First-come, first-served

Closest cylinder next

Elevator algorithm, initially moving down (towards lower cylinder end)