Good Riddles

Question: I give advice to others,
yet I know nothing myself.
I am a hitchhiker destined to stay still.

Question: You are in a car with some helium balloons and hit the gas. While you accelerate, which way does the balloon move?

Question: I am first in earth A second in heaven I appear twice in a week But you can only see me once in a year You can also see me in the middle of the sea What am I?

Question: What does a black woman and the bottom of my shoe have in common?

Question: At the beginning of the first day of school there was a dead boy found inside of a classroom. They found 3 suspects: The janitor, the teacher and one of the boy's classmates. The janitor claims that he was just cleaning the room, the teacher said that she was computing her student's grades and the boy's classmate claims that he was listening to music.

Who committed the crime?