Four jobs are waiting to be run. Their expected run times are $$6, 3, 5$$ and $$x$$. $${\rm I}$$n what order should they be run to minimize the average response time?

Four jobs to be executed on a single processor system arrive at time $${0^ + }$$ in the order $$A, B, C, D.$$ their burst $$CPU$$ time requirements are $$4, 1, 8, 1$$ time units respectively. The completion time of A under round robin scheduling with time slice of one time units.

The sequence $$.........$$ is an optimal non-preemptive scheduling sequence for the following jobs which leaves the $$CPU$$ idle for $$..........$$ Unit (s) of time

The details of an interrupt cycle are shown in Figure
Given that an interrupt input arrives every $$1$$ $$msec,$$ what is the percentage of the total time that the $$CPU$$ devotes for the main program execution.