Solve with stochastic modeling

(40 points) A small engine repair shop is run by two mechanics where people bring various types of equipment for repair. The shop is willing to accept all equipment that customers bring in. However, unfortunately, when the customers see the floor of the shop covered with waiting jobs, they go elsewhere for more prompt service. The shop floor can house a maximum of 2 equipment, excluding those being serviced. The customers arrive at the shop every 10 minutes on the average, and it takes a mechanic an average of 20 minutes to complete each job. Both the interarrival and service times are exponential. Determine the following quantities in steady-state: a. (30 points) Average number of idle mechanics. b. (5 points) When there is one equipment in the line, what is the probability that a customer arrives before a job is completed