The first one is right.

The second... It's a math riddle. I don't smoke cigars, so I don't know how literally it's supposed to be taken.

The third is the trick-trick question, so no. But then, I guess that pretty much gives away the trick. I'll post up the explanation in a bit if nobody else can guess it.

And the fourth isn't even close to being right.

What is it they say about silence being golden?