There are 13 guests at a hotel and 3 rooms, one with 2 beds, one with 3 beds, and one with 4 beds. If nine guests are chosen at random and placed randomly into one of the rooms, assuming you are one of the guests, what is the probability that you will be chosen and will be in the room with 2 beds?

If someone please explain the logic behind solving this question, I'd be real grateful because I have no idea where to start.