A uni-processor computer system only has two processes, both of which alternate $$10$$ $$ms$$ $$CPU$$ bursts with $$90$$ $$ms$$ $${\rm I}/O$$ bursts. Both the processes were created at nearly the same time. The $${\rm I}/O$$ of both processes can proceed in parallel. Which of the following scheduling strategies will result in the least $$CPU$$ utilization (over a long period of time) for this system?

Draw the process state transition diagram of an $$OS$$ in which
(i) each process is in one of the five states: created, ready, running, blocked (i.e. sleep or wait), or terminated, and
(ii) only non-preemptive scheduling is used by the $$OS.$$ Label the transitions appropriately.

Which combination of the following features will suffice to characterize an $$OS$$ as a multi-programmed $$OS?$$
$$(a).$$ More than one program may be loaded into main memory at the same time for execution.
$$(b).$$ If a program waits for certain events such as $$I/O$$, another program is immediately scheduled for execution.
$$(c).$$ If the execution of a program terminates, another program is immediately scheduled for execution.

Which of the following does not interrupt a running process?