a$)$ A computer has a hard disk that rotates with a speed of $7200$ RMIrotations per minute, and kit a reported seek time of $5$ ms and transfer time of $2$ MBytes$/$s$.$ The hard disk has $8$ plater, $1$a$.$ tracks per platter, $256$ sectors per track, and each sector has $512$ bytes$\mathrm{.}15$ marks$)$a$.$ What is the average access time of the hard disk, in ms$?$b$.$ What is the capacity of the hard disk, in Mbytes?