Q36,P2,J15.A disk drive has 100 cylinders,numbered 0 to 99. Disk request come to the disk driver for cylinders 12,26,24,4,42,8,50 in that order. The driver is currently serving a request at cylinder 24. A seek takes 6msec per cylinder moved. How much seek time is needed for the shortest seek time first (sstf) algorithm?

A)0.984 sec          B)0.396 sec          C)0.738 sec                 d).42sec.

Answer D.

Explanation.

current position of head is at cylinder 24.
24->26->12->8->4->42->50.
total cylinders traversed are.(2+14+4+4+38+8)=70 cylinders.
1 cylinders is traversed in 6 ms.
70 cylinders are traveresed in 420ms.= 420s/1000=.42sec