12 balls. One heavier or lighter. Three weighings to identify which and whether heavy or light. A great puzzle. And it's been great fun producing a simulation that you can test your ideas on.

I encountered this great puzzle back in the 50's and managed to solve it about 20 minutes. I still love it!

I regard this as one of the cleverest puzzles I have ever encountered - maybe you will too!

I don't think I managed to solve this one when I first encountered it. Maybe you'll do better!

This one I spent many hours on and never really cracked it.

One of those puzzles where it's easy to go down a tortuous path (pun intended!). Be on the lookout for an 'Aha!' solution.

Fiendishly difficult to create but relatively easy to solve. You also have the choice of using straight or cryptic clues.

I've decided to create web versions of some of my favourite word puzzles - enjoy!