A hiker comes across an intersection where three roads cross. He looks for the sign indicating the direction to his destination
city. He finds that the pole carrying three city names and arrows pointing to them has fallen. He picks it up, considers it, and pops it back into place, pointing out the correct direction for his destination. How did he do it?
Answer: He knew which city he had just come from, He had pointed that arrow back toward his starting point, which oriented the signs properly for his destination and a third city.
