What does this simple rebus mean?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

What does this rebus means ?

PROG WORKRESS

I am the fastest animal but cannot climb the tree. What am I?

John was gifted a new Hayabusa. He drove x miles at 55mph. Then he drove x+20 miles at 40mps. He drove his bike for 100 minutes. How much distance did he travel?

What is the last thing you take off before bed?

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

You are playing a game with your friend Jack. There are digits from 1 to 9. You both will take turn erasing one digit and adding it to your score. The first one to score 15 points will win the game.

Would you want to play first or second?

PS: The sum should be exactly 15.

When is the top of a mountain similar to a savings account?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?