Someone already posted this but the answer is wrong:

Problem 1: Disk drive problem.

Given the following parameters: Single-platter disk, rotation speed: 7200 rpm , number of tracks on one side of platter: 3,000 , number of sectors per track: 600 , seek time: 1 ms for every 100 tracks traversed (This is not the real basis for seek time as your reading of the external link for this lesson should have shown, but it gives you data to come up with a number without working through g forces, strength of materials, and everything that really plays a part.) Disk receives a request to access a random sector on a random track. Assume the head starts at track 0.

a. What is the average seek time?

b. What is the average rotational delay?

c. What is the transfer time for a sector?

d. What is the total average time to satisfy a request?