3 Metal Spheres
The Board of Trustees of a nearby University, decides to test the Professors, to see if they really know their stuff. First they take a Math Prof. and put him in a room. Now, the room contains a table and three metal spheres about the size of softballs. They tell him to do whatever he want with the balls and the table in one hour. After an hour, he comes out and the Trustees look in and the balls are arranged in a triangle at the center of the table. Next, they give the same test to a Physics Prof. After an hour, they look in, and the balls are stacked one on top of the other in the center of the table. Finally, they give the test to an Engineering Prof. After an hour, they look in and one of the balls is broken, one is missing, and he's carrying the third out in his lunchbox.