Question: How long do you have to walk to burn off 100 calories?

  Options: 
 A. Walking at about a mile every 15 minutes, you would walk for 30 minutes, or 2 miles. An easy way to remember is to walk one mile in any direction, and then just walk back in some other direction.
 B. Walking at about a mile every 15 minutes, you would walk for 30 minutes, or 2 miles. An easy way to remember is to walk one mile in any direction, and then just walk back in the opposite direction.
Answer: B