What kind of room is left on the 7th floor?

M: I’d like a single room for tonight.
W: Yes, sir. Have you booked a room?
M: I’m scary I haven’t.
W: Let me see. With or without a bath?
M: I’d prefer a room with a bath.
W: We have a room at front with a bath on the 5th floor. If you prefer a room at back, it’s on the 7th floor, but without a bath.
M: How much are they?
W: The room with a bath is seventy dollars and the one without is fifty dollars. The cost is lower by the week.
M: Thanks, but I’m planning to stay only overnight. I’ll take the room with a bath. What time do I have to check out?
W: 11 o’clock, sir. Will you please write down your name here? The bell-boy will take your bags and show you your room, which is 509. Here is the key.