2. Tamika is on page 20 of her book and reads 4 pages every night. Mark is on page 30 of the same book and reads 2 pages every night. How long will it take Tamika to be further in the book than Mark?

Suppose that a disk drive has 5,000 cylinders, numbered 0 to 4,999. the drive is currently serving a request at cylinder 2,150, and the previous request was at cylinder 1,805. the queue of pending requests, in fifo order, is: 2069, 1212, 2296, 2800, 544, 1618, 356, 1523, 4965, 3681