Math 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: There are these polar bears. And one day they decide to go fishing. So they go out on the ice, they cut a hole, and they sit around it. They catch 2 Karp and 7 Blue Gill. They say, that was some good fishing. Let's roll the dice. They role a 4 and a 3. How many polar bears were there?

Question: Name 4 ways to calculate 1+1.

Question: The Duke of Riddleton has been kidnapped. The police have identified 3 suspects, all of which had motive, and opportunity to do the deed. Their names are Andrew, Jason, and Shawn. All of them claim that they didn't do it, but Jason and Shawn seemed nervous wile being questioned. There was a note left behind, with the following description: 1491011. Who kidnapped the duke?

Question: Why is 12 divided in half 7?