A disk has a average seek time of 4ms (milliseconds), a rotational speed of 5400 rotations per minute. Each track on the disk has 16 sectors, each of 1Kbyte, and the transfer from disk to main memory proceeds at the rate of 20Mbytes/second.

a. What is the average access time of this disk for reading one sector?

b. A 1.2Ghz computer containing the above disk loads a program of size 10Kb stored in sequential sectors on the same track. No disk cache is present. Thereafter it executes the program for 600 million cycles. What percentage of the total (disk + CPU) time is spent accessing the disk? Assume an average seek time and rotational latency.