Good Riddles

Question: How many letters are in the alphabet?

Question: What is the best way to keep your hat from falling off your head?

Question: Round like a dishpan and smaller than a bathtub.But the ocean can't fill it.What is it?

Question: When you do not know what I am, then I am something. But when you know what I am, then I am nothing. What am I?

Question: A deaf and mute man goes to the train station. Tickets for the train are 50 cents each. The man goes to the ticket booth and hands the man inside just a dollar. The man in the booth hands him two tickets.

How did the man in the booth know to give him two tickets without even looking at him?