A rectangular room measures 7.5 meters in length and 3 meters in width, with a height of 3 meters. A spider is positioned 25 centimeters down from the ceiling in the middle of one of the short walls. A sleeping fly is located 25 centimeters above the floor in the middle of the opposite wall. The spider wants to walk to the fly (i.e., move only along the walls, floor, or ceiling) to catch it.

The question: How can the spider reach the fly, walking just 10 meters?

The answer: Click here!