This riddle says a man has five boxes. One is described as empty, yet he still says all five boxes are full. How can both statements make sense?
The trick is that “empty” usually means a box contains no ordinary objects. It does not necessarily mean that absolutely nothing is inside it.
Answer: The “empty” box is full of air.
Unless a box is in a vacuum, the space inside it contains air even when we casually call it empty. The riddle plays on the difference between everyday language and a more literal interpretation of the word “full.”
