Consider a hard disk with the following specifications:

$3\mathrm{.}5$in diameter

$3600$RPM

$20$ platters, and $2$ surfaces per platter

Capacity: $40$GB

Number of cylinders: $1024$

$1$ block $=4$KB

$20\%$ overhead between blocks $($gaps$)$

Average seek time: $10$ms$.$

Compute the following:

the average time to access a block?

the average time to read $4$ adjacent blocks?

the average time to read one track, starting at a specified location?

Which of the following is true about the above computation?

$$

$$a$)$The average time to read $4$ adjacent blocks is approximately $8\mathrm{.}6$ms$$b$)$The average time to read $4$ adjacent blocks is approximately $18\mathrm{.}4$ms$$c$)$The average time to access a block is approximately $18\mathrm{.}4$ms$$d$)$The average time to access a block is approximately $10\mathrm{.}1$ms$$