10. In a file system based on contiguous allocation, estimate the execution time of the following four code fragments. Assume that the disk sector size and the block size are the same: 500 bytes. Assume that it takes 5 microseconds to read a sector from the disk, the overhead of a system call is 1 microseconds, and it takes no time to copy data from the system space to the user space and to fetch and execute instructions. a) for ( 1-0; i