3. Consider a disk queue with I/O requests on the following cylinders in their arriving order: 55,58,39,18,90,160,150,38,184 We assume a disk with 200 tracks and the disk head is initially located at track 100. Write the sequence in which requested tracks are serviced using the SCAN algorithm and calculate the total head movement (in number of cylinders) incurred while servicing these requests. (6 marks)