Don't ask me

I have a clerical type job that involves talking with the public. Sometimes I get asked really dumb questions. I'm not talking about questions that people ask because they are looking for information or clarification; in this case there are no dumb questions. I'm talking about questions that fly in the face of good old common sense. Questions that leave me speechless because I think, "What you just asked me can't be what you meant to say". Here is a recent example:

Caller: Good morning. May I speak to Ms. Hill?
Me: Ms. Hill is not here today.
Caller: So what time do you expect her in?
Me: (pausing - see because I figure he didn't mean to ask what time will someone be in that I already said is out for the day. I'm trying to think of an answer to his question without being rude or sarcastic.) Umm, she's not here today.
Caller: Oh, so she won't be in at all! (hangs up)

What could I have said differently? Where was the breakdown in communication? Here is another gem:

(The setting - I am in the lobby by the elevators on the 1st floor)
Guy: We have to go to room 4xxx on the 4th floor.
Me: OK
Guy: Is that 4 floors up or down?
Me: (speechless again! How am I to answer this??!!) It's on the 4th floor.

Again, what was I to have said? He already knew what floor his destination was on so it's not like he was asking which floor 4xxx was on. That I could answer. Let's even say that he didn't know he was on the first floor, his best bet would still be to get on the elevator and press "4".

Speaking of elevators, I just remembered another:

(The setting - I am on the elevator and the elevator stops at a floor)
Man: (putting his head in the elevator and looking around) Does these elevators go to the basement floor?
Me: (actually I didn't say anything at all. I figured that if he go on and saw the button marked "B" that would clue him in)

Actually, I can cut the guy some slack for asking this. I know that in high rise buildings with scores of stories there are express elevators that only go to certain floors. In that situation, his question would be valid. My office building has 9 floors. Only 9. Did he really think we have express elevators that don't go all the way up and down? Maybe his elevator doesn't go all the way to the top.