Here's a simple puzzle that you can do yourself with just six identical coins. All you have to do is move around the coins, starting with a triangle and ending with a hexagon.
Easy, right? But don't start yet! I have to tell you the rules:
- Slide one coin at a time.
- Keep the coin flat on the table at all times. Do not push or move any other coins.
- When you've finished sliding a coin, that coin must be touching at least two other coins.
- Finish in the least possible number of moves.
The first person to solve it gets a cupcake and six coins! (This blogger is not responsible for providing aforementioned cupcake or coins.)
Update: The solution is now available. Cupcakes are not.