Ja. We have a small portable disk which spins at 16000 rpm (revolutions per minute). The disk is formatted to hold only one sector per track cylinder). From a stationary position, the read/write (r/w) head requires 8 ms (milliseconds) to move to the first adjacent track, and then 3 ms to move to each additional track (in the same direction) once it starts to move as long as it does not stop at some intermediate track. Currently, the r/w head is stationary at track 61. A particular file is exactly 6 sectors long and stored contiguously on disk starting at track 72. The goal is to read exactly one half of the file starting at the beginning of the file. What would be the average time to perform the read operation? Show your work. b. For a RAID based disk system, select a single RAID level that is suitable for parallel I/O but not at all suitable for increasing reliability. Explain the rational for your selection.