Answer:
What is black when you buy it red when you use it and gray when you throw it away?
If a man carries my burden they will get crushed to death. Though not rich I leave silver in my track.
I have two bodies joined together as one. When standing still, I run and run. What am I?
The more you take, the more you leave behind. What are they?
I grow up while growing down
A man goes out in heavy rain with nothing to protect him from it. His hair doesn't get wet. How does he do that?