Kids Riddles

Question: How do you make the number one disappear by adding to it?

Question: When do you go at red, but stop at green?

Question: What's black and white and red all over?

Question: I am an instrument that you can hear, but you can not touch or see me.

What am I?

Question: A cowboy rode to an inn on Friday. He stayed two nights and left on Friday. How could that be?