The Returning Explorer: A Word Problem with a little math involved.
You surely been exposed to the classic riddle at some point in your life. An explorer walks ONE MILE due SOUTH, turns and walks ONE MILE due EAST, turns again and walks ONE MILE due NORTH. He finds himself back where he started. He shoots a bear. What color is the bear? The traditional answer is of course “White”, because he’s a polar bear, right? The explorer must have started at the North Pole to walk in these directions for these distances, etc. etc…
Not long ago, someone made an interesting discovery using logic and mathematics– the North Pole is not the only starting point that satisfies the given conditions of South, East, North, Bear. Can you think of any other spot on the planet from which you can walk a mile South, a mile East, a mile North and find yourself back at your original location? Since I like bears we’ll omit the shooting-a-bear element out of the problem.
Credit: Martin Gardener, Scientific American, 1970s..