Situation: I am standing and signing a document on top of the desk and right behind me is a corridor. I am also facing the blackboard.
Alternative situations: While placing my answer booklet on the desk, I can see my lecturer rubbing the blackboard on my 10 o'clock direction. While I was given a lecture in a room, my backpack was placed on a chair.
Question: Can the number of chairs behind me be divided by three?