Past exam of the year 1 of the computer science course of the University of Oxford / 2017 / Digital systems, linear algebra, introduction to formal proof / 2 / e / Solution

Use round-robin scheduling with scheduling quantum 2 ms. A's first burst is split by B, and A's second burst is also interrupted once. The resulting CPU intervals areA blocks for input-output during $[5,7)$ and $[12,14)$; B blocks during $[3,5)$ and $[6,8)$. At time 8, B joins the ready queue while A uses the remainder of its current quantum; B runs at time 9. No other process is runnable during A's final four milliseconds, so A can continue across the time-16 quantum boundary. Consequently