Describe how the disk arm moves to satisfy all the pending requests for each of

Describe how the disk arm moves to satisfy all the pending requests for each of the following disk-scheduling algorithms.
FCFS
SSTF
SCAN.
Calculate the total distance (in cylinders) that the disk arm moves for each of the above disk-scheduling algorithms. Compare the algorithms and explain which algorithm is the most efficient (the shortest distance) for this scenario.
Compare the algorithms and determine which is the fairest for the next process in the queue. Explain why this algorithm will always be the fairest disk-scheduling algorithm.
Describe an example of circumstances where fairness would be an important goal. Describe a scenario where it would be important that the operating system be unfair.