Q30

Suppose the following disk request sequence (track numbers) for a disk with $100$ tracks is given: $45, 20, 90, 10, 50, 60, 80, 25, 70.$ Assume that the initial position of the R/W head is on track $50$. The additional distance that will be traversed by the R/W head when the Shortest Seek Time First (SSTF) algorithm is used compared to the SCAN (Elevator) algorithm (assuming that SCAN algorithm moves towards $100$ when it starts execution) is________________tracks.