Solving riddles and puzzles is an excellent way to exercise the mind, which needs constant stimulation just like any other muscle in the body. In a previous article, we challenged our readers to find hidden things in these 4 postcards, and today, we’re bringing you a whole new series of images...

John is trapped in a room. There is a table, a chair, 2 doors and a small hole in the ceiling (6 inches in diameter) there. Behind the first door there’s an extremely hungry lion that hasn’t eaten for a couple of days. Behind the second door there’s a glass tunnel that magnifies the...