53. Assemblers at a job-shop are required to submit materials requisition forms in person to a store clerk at the warehouse to get parts for their current project. The requests for parts are modeled by an exponential distribution with a mean of 15 minutes. A store clerk can handle 10 requests per hour. Answer the following questions assuming that there is 2 clerks on duty. a. On average, how many assemblers would be at the counter, including those being served? b. What is the probability that an assembler would have to wait for service? c. If an assembler has to wait, how long would the average wait in line be? d. What percentage of time are the clerks idle? e. If clerks cost $20 per hour and assemblers cost $40 per hour, what number of clerks would be optimal in terms of minimizing cost