What is black when you buy it, red when you use it, and gray when you throw it away?

Living above a star, I do not burn
Eleven friends and they do not turn
I can just be visited in a sequence, not once or repeatedly
PQRS are my initials
Can you tell my name accurately?

A man is looking at a photograph of someone. His friend asks who it is. The man replies, “Brothers and sisters, I have none. But that man’s father is my father’s son.” Who was in the photograph?

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle:

I don't get anymore wetter, no matter how much rain falls on me.

Where do fish keep their money?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

If eleven plus two equals one, what does nine plus five equal?

Speaking of rivers, a man calls his dog from the opposite side of the river. The dog crosses the river without getting wet, and without using a bridge or boat. How?

John was piloting a plane behind a car but was never able to overtake it. Why?