4. Consider a 500GB, 7200rpm disk. Each track on the disk has 128 sectors and each sector is 1KB. The disk arm traverses the tracks at 0.1 msec per track and requires a start up time 0.2msec. A file system is built on top of this disk and the size of each file block is 8KB. Note that a file block is always allocated contiguously on the disk. Consider a file of size 80KB. The file is allocated on the disk using indexed allocation scheme and the index table is kept in memory. The file contains 10 file blocks, which are allocated on tracks 105, 120, 112, 101, 113, 106, 116, 108, 111, and 115. Assume that the disk has a 1MB buffer and it uses the Scan algorithm for disk arm scheduling. Compute the time required to access the entire file. (Assume that there are no other disk access requests in the system and the current disk arm is at track 0.)