Matthew Speedster drove up a mountain road at 50 kilometers per hour. He turned around instantly at the top and drove back down the same road very fast. He wanted to be sure that when he got back to his starting point, the complete trip would average 100 kilometers per hour.
How fast does he need to travel coming down the mountain?
When you finish this problem, please share your answer and your thinking with Mr. L. He may have some follow up questions for you to consider.
