To keep track of free blocks in a file system, one of the two approaches is generally used - using bitmaps (bit vectors) or using linked lists. Consider that the linked list approach is used to keep track of free blocks in a file system. Assume that the disk size is 16 GB , block size is 2 KB , and block numbers used are 32-bit long. A single pointer of size 4 bytes is used in each block of the list to point to the next block of the list. The number of blocks required to hold the free disk block numbers is $\_\_\_\_$ (answer in integer)

Note: $1 \mathrm{~K}=2^{10}$ and $1 \mathrm{G}=2^{30}$

Consider a hard disk with a rotational speed of 15000 rpm . The time to move the read/ write head from a track to its adjacent track is 1 millisecond. Initially, the head is on track 0 . The number of sectors per track is 400 . The sector size is 1024 bytes. It is necessary to transfer data from 10 randomly located sectors in each of the following tracks in the order: 5,12 and 7.

The total time for the data transfer (in milliseconds) from the hard disk is $\_\_\_\_$ . (rounded off to one decimal place)

Consider a disk with the following specifications: rotation speed of 6000 RPM, average seek time of 5 milliseconds, 500 sectors/track, 512-byte sectors. A file has content stored in 3000 sectors located randomly on the disk. Assuming average rotational latency, the total time (in seconds, rounded off to 2 decimal places) to read the entire file from the disk is _________