Logic Riddles

Question: A man wanted to enter and exclusive club, but did not know the password to get in. He waited by the door and listened. The doorman said "Twelve" and the other man said "Six" and was let in. A second member came up and the doorman said "Six" to which the member replied "Three" and was let in. The man went up and the doorman said to him "Ten" the doorman said "Five" but was not let in. Why?

Question: What does this code mean?: YY U R YY U B I C U R YY 4 ME

Question: A man who couldn't speak went into a store to buy a toothbrush. He pretended to brush his teeth with his finger to tell the cashier what he wanted. The cashier understood and the man went home with the toothbrush. Then, a blind man came into the store wanting to buy sunglasses. How could he tell the cashier he wanted sunglasses?

Question: A woman was reading in the basement when her husband, thinking the basement was empty, turned off the light. The woman continued reading. There were no lamps or flashlights and the light her husband turned off didn't come back on. How was the woman able to read?

Question: Fifty is my first, my second is the third in fourth, and my end is the end of an ending. With a nut I become a nut that isn't, and without one I move.