Good Riddles

Question: Had by few but treasured by all,
I'm on the inside and outside and I make men fall.

What am I?

Question: When is 99 more than 100?

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?

Question: What am I?

Question: Imagine you are swimming in the ocean and a bunch of hungry sharks surround you. How do you get out alive?