Consider three process, all arriving at time zero, with total execution time of 10, 20 and
30 units respectively. Each process spends the first 30% of execution time doing I/O, the next
40% of time doing computation, and the last 30% of time doing I/O again. The operating
system uses a round robin scheduling algorithm with time quantum 2 and schedules a new
process either when the running process gets blocked on I/O or when the running process
finishes its compute burst. Assume that all I/O operations can be overlapped as much as
possible. For what percentage of does the CPU remain idle?