My ex-wife was.....wellllll...let's just say "not the sharpest knife in the drawer."  Actually, she was about as sharp as a marble.

Once we were talking to a salesman about buying some new furniture.  He checked his calculator, then told us, "Well, folks, you pay $50 down, and then you don't pay anything else for three months."  She gave him an incredulous look, and said, "How the hell did you find that out?"  8-)

She also had a problem with getting her quotes just right, too.  She told me once, "OK.  You've made your bed.  Now lie about it."