This problem has appeared in several collections of mathematical brain-teasers and from time to time gets resurrected to challenge yet another generation of puzzlers.

The problem can be stated as follows. We arc given twelve balls, identical in appearance but one of which is a tiny bit either heavier or lighter than the other eleven.

We are allowed only three weighings with a balance scale, to determine which is the odd ball and to find whether this ball is heavier or lighter than the others.

Give it a go?

Alan

Balance scale like the one often seen in a court of law, of course you do not need an actual balance scale just imagine it.

**You can get the solution on the internet but that would spoil it for those who want to solve it on their own bat, so to speak?**