You were playing ping pong with your friend. Suddenly the ball fell into a narrow metal pipe that was imbedded in the concrete surface of the floor one foot deep. Now you don't have any other ball and you desperately want to take it out and play. You and your friend have your shoelaces, your tennis paddle and a plastic water bottle. However, the bottle cannot fit into the pipe.
How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?
A Car driver was heading down a street in Washington. He went right past a stop sign without stopping, he turned left where there was a 'no left turn' sign and he went the wrong way on a one-way street. Then he went on the right side of the road past a cop car. Still, he didn't break any traffic laws. Why not?
Artificial Intelligence has crushed all human records in the puzzle game “2048,” achieving a high score of 839,732 and beating the game in only 973 moves without using any undo.