Jobs sent to a printer are held in a buffer until they can be printed sequentially on a first come, first served basis

Jobs sent to a printer are held in a buffer until they can be printed sequentially on a first come, first served basis. Jobs arrive at the printer at the rate of 10 per second. The average time to print a job is five seconds. Assuming an M/M/1 system, use R to simulate the queue 10,000 times and use this to:

(a) find the expected value and standard deviation of the number of jobs in this system at any time.

(d)   estimate the probability that a submitted job will be printed immediately.