You should know that a whole circle consists of 360 degrees. Since the problem states that an angle measures 75 degrees you would then realize it is 75 degrees out of 360 degrees, or 75/360. This simplifies to 5/24.
I would love to help you but I don't have time because I really have to get this assignment done but if someone doesn't answer then later I will but I just want to let you know that your teacher sounds like a terrible person and I am really sorry she put you in that situation