(Please do not copy from the other answers or else you will receive a downvote)

Three identical machines operate independently in a small shop. Each machine is up (i.e. works) for between 7 and 10 hours (uniformly distributed) and then breaks down. There are two repair technicians available, and it takes one technician on average 2.5 hours (exponentially distributed) to fix a machine. Only one technician can be assigned to to work on a machine even if the other technician is idle. I fall three machines are broken at a given time, the third machine joins a repair queue and wait for the first available technician. A technician works on a machine until it is fixed, regardless of what else is happening in the system. All uptimes and downtimes are independent of each other. Starting with all machines at the beginning of an uptime, simulate this for 160 hours making 10 replications and observe the time average number of machines that are down (in repair or in queue for repair), as well as the utilization of repair technicians as a group. (HINT: consider the machines as entities and note that there are always 3 machines in the model and they never leave.)