A bar is very busy and one person did not show for their shift. a guest says he is in a hurry and you already have three tables that sat down before him. what do you do

The best way to handle this situation is to tell to the guest who is in a hurry that you won't be able to take his request as the top priority because there are others who are first in line before him. It would be best to advice him that his order would still be taken care of and would do it as fast as it can with trying to explain that he's not the only one in the restaurant to assure him and prevent conflict.