Consider a disk system with 100 cylinders. The requests to access the cylinders occur in the following sequence : 4, 34, 10, 7, 19, 73, 2, 15, 6, 20 Assuming that the head is currently at cylinder 50 , what is the time taken to satisfy all requests 1 ms if it takes to move from the cylinder to adjacent one and the shortest seek time first policy is used?

1. A357 ms
2. B238 ms
3. C276 ms
4. D119 ms

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Correct answer: D. 119 ms

Explanation

From 50: 34, 20, 19, 15, 10, 7, 6, 4, 2, then 73: 16 + 14 + 1 + 4 + 5 + 3 + 1 + 2 + 2 + 71 = 119 cylinders × 1 ms.