Its a trick question and the answer has been hidden within the question itself. It is clearly mentioned that the walls are pink and floor is pink and also that is a one-storey house. Had it been two-storey house, or an have an attic or something with an upper landing, then the question would have been relevant.
Especially in the days before audio recording and playback, music was often written out as a means of preserving and communicating it. To do this, a system of notation was developed that gives musicians the information they need to play music as the composer intended it.
