Consider a magnetic disk consisting of 16 head and 400 cylinders. This disk is divided into four 100-cylinder zones with the cylinders in different zones containing 160, 200, 240 and 280 sectors, respectively. Assume that each sector contains 512 bytes, average seek time between adjacent cylinders is 1 msec, and the disk rotates at 7200 RPM.

Calculate the (a.) cylinder skew and (b.) average data transfer rate.