Three lunatics

Three lunatics approach their Asylum doctor with a request for a weekend pass to the local city. "That's impossible says the doctor. You're all nuts. You'll get lost and never come back." But, the lunatics wouldn't relent until finally, exasperated, the doctor says "OK! If you can answer a simple question I'll sign the pass." He turns to the first lunatic and says "What's three times three?" The lunatic starts counting on his fingers "3, 7, 19, 38?. Is it 128?" The doctor shakes his head and turns to the next lunatic: "What's three times three?" The lunatic immediately shouts "WEDNESDAY!" The doctor, beginning to get disgusted turns to the last lunatic: What's three times three?" The lunatic thinks for a moment and then asks for a pencil and a piece of paper. That provided, she writes for some time furiously, and finally looks up and says "Nine." The doctor is amazed, but true to his word he begins filling out the pass. As he's writing he says "This is incredible, you've always been thoroughly insane. How'd you do it?" The lunatic responds, "Oh, it was easy I divided 128 by Wednesday!"