A princess wants to marry a cobbler. The King wants her to marry a Baron. The King decides that if she pulls the white stone from a bag containing a white stone and a black stone she can marry the cobbler, but puts two black stones in the bag. The princess knows the King is trying to trick her, and manages to marry the cobbler. How?
This is a really old one, but it usually involves a table. In the interest of not having to slightly rephrase an answer someone has already submitted, this is the answer that was posted on page 12:
Look in the mirror, see what you saw, get the saw and saw the table in half. Two halves make a whole. Go out the hole.
Except for this one, I suppose you would saw the mirror in half instead of a table.
The solution to the princess and the king puzzle is that the princess pulls one stone out of the bag and tosses it away. She then pulls the second stone out. The king can't admit lying so is forced to submit.
You don't need a mirror to see "what you saw". That alone ruins the riddle. The puns don't help either.
It's an old riddle for children, thought up by children. It doesn't follow logically at all; the puns are the whole point. One could argue that it is "thinking outside the box", but it's one of those riddles nobody can answer without having heard the answer before since it's such a "creative" solution.
At least the riddle where you imagine you're in a room with no windows or doors has some logic to its answer. Still, you can't expect quality riddles from schoolchildren.