Good Riddles

Question: Filled with garb,
the price is free.
Just return what you don't need.

What am I?

Question: A semi truck is driving down the highway but the driver isn't paying attention. He goes under an overpass that is too short for his truck by only inches and gets stuck. He thinks it's going to be a very costly mistake but one of his friends happens to pass by and explains to him how he can get out in the matter of minutes without any help.

What does he suggest?

Question: You have a cube made of 10 x 10 x 10 smaller cubes, for a total of 1000 smaller cubes. If you take off 1 layer of cubes, how many remain?

Question: Paul is 20 years old in 1980, but only 15 years old in 1985.How is this possible?

Question: I am shorter when I stand and taller when I sit.
Sometimes I'm even called a pit.

What am I?