Logic Riddles

Question: You are surrounded by a 100 foot wide and 100 foot deep moat. You have a 40 foot tall ladder, matches, a gallon of water, and as much rope as you need.

How can you get across the moat?

Question: When angry it turns red, cold it turns blue and pale when scared.

Question: what goes down but never goes up?

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 number when divided in half becomes zero?