$13\mathrm{.}1$ The results of running Skippy are shown for a mock disk $($Disk Alpha$)$ in Figure $6\mathrm{.}25$

a$.$ What is the minimal transfer time?

b$.$ What is the rotational latency?

c$.$ What is the head switch time?

d$.$ What is the cylinder switch time?

c$.$ What is the number of disk heads?