Four programs, Job $1,$ Job $2,$ Job $3$ and Job $4$ are submitted for execution at the same time. If it is a simple uni$-$programming environment, these jobs will be executed in a sequence i$.$e$.$ Job $1$ then Job $2$ then Job $3$ and then Job $4.$ For a batch multi$-$programming environment, all of the jobs will be executed at once in a batch. It is noted that Job $1$ completes in $3$ seconds, Job $2$ completes in $10$ seconds, Job $3$ also completes in $10$ seconds and Job $4$ completes in $7$ seconds from the time they begin executing.