a$)$ Consider a Hard Disk Drive $($HDD$)$ that rotates with a speed of $10000$ RPM $($Revolution Per Minute$)$ and has an average seek time of $10$ milli secs$.$ Compute the time required for reading data from one complete track. Each track comprises $100$ sectors of $512$ bytes each.

$[3$M$]$

b$)$ Consider a RAID $4$ disk array with $4$ data disks and one parity disk, as shown below. Assume each block size is $6$ bits. Calculate the values of X and Y $.$

$[2$M$]$