19. Calculate the number of disk tracks traversed using the FCFS, SSTF, SCAN, and LOOK algorithms for the series of disk track service requests given below. At the time the first request arrives in the disk request queue, the read/write head is at track 50, moving toward the outer (lower-numbered)

tracks. (Hint: Each track over which the disk arm passes counts in the total, whether or not the track is read.)

54, 36, 21, 74, 46, 35, 26, 67 20. Repeat the previous problem using the following tracks:

82, 97, 35, 75, 53, 47, 17, 11