The pharmacy of a large metropolitan hospital has a counter used exclusively for nurses' requests for medications. The time between requests is estimated to be about five minutes. A pharmacist can handle requests at a rate of 15 per hour. Suppose there are two pharmacists at the counter.
a. On average, how many nurses would be at the counter, including those being served?
b. If a nurse has to wait, how long would the average wait be?
c. What percentage of time are the pharmacists idle?
d. If pharmacists represent a cost of $28 per hour and nurses a cost of $24 per hour, should the pharmacy employ one, two or three pharmacists in order to minimize total cost?