For the applets below, if you do calculations by hand, keep at least 4 significant figures on numbers that aren't whole numbers. That way you'll come close enough to the answers I'm expecting so that I can tell if you are right. The applets below will call your answer right if you are within 0.002 of the right answer.
Times are in hours.
Unless stated otherwise, use the usual assumptions about the distribution of the arrivals and service times, and about queue priorities. In these applets, click on a small box and type in your answer. Press Enter to see if you're right. You can press Tab to move right from one box to the next, or Shift-Tab to move left, rather than having to reach again for the mouse. The doc spends an average of 15 minutes with each patient.