Is it true that multiprogramming system execute each job faster?

No, it's not true that multiprogramming systems execute each job faster. Instead, multiprogramming increases overall system efficiency by allowing multiple jobs to reside in memory and share CPU time, which reduces idle time and maximizes resource utilization. However, the execution time for individual jobs may remain the same or even increase slightly due to context switching overhead. The primary benefit is improved throughput and resource management rather than faster execution of each job.