I've just been playing around with the fish-teaser that cropped up on a blog link this afternoon. Reputedly written by Einstein he also pronounced that only 2% of the population could solve the problem though smart as he was I'm not entirely sure where he plucked that figure from.

There is however a way to do the fish problem visually that makes it fairly straightforward. One that I'd be intrigued how to simplify however is the following which kept me tied up for hours at a July 4th party (back in the days before entrepreneurship when I could afford to be cavalier with social contact).

Pauli's steel

I'm not sure who invented this but for the sake of keeping up with the Jones', let's say that it was Pauli. Apparently the little devil is soluble by only 1% of the population though that could be something to do with the phenomenon that everyone who solves it immediately forgets the answer to Einstein's riddle and vice versa. Strange.

Odd-ball out

You are presented with 12 steel ball bearings and a set of weighing scales. All the ball bearings are identical except for one. That single bearing has the same size and appearance as all the others but a different mass. You don't know whether it is heavier or lighter than the others, all you know is that it's different.

Ethan, your mission is to find out which ball is the odd one out and to do this you may use nothing but the scales. Furthermore, you are limited to three weighings and three weighings only. That means that you can put any combination of balls on the scales, note the outcome and repeat the process two more times but that is it.

You can't drop the balls, roll the balls, taste the balls or do any other form of jiggery-pokery. This is not a trick problem, there is a solution and it is a unique solution (Update: it's not a unique solution at all! It seems there are at least five solution combinations and possibly more). If you want a very basic clue then see the bottom of this post.

The winner will be the first person to post an answer on comments of the next blogpost after this post. DO NOT POST YOUR ANSWER ON THIS POST as it will spoil it for other people.

(disclaimer: this post was a little pithier half an hour ago but then Blogger decided to delete the whole thing - grrrrrrr)

Clue - highlight to bring to life:
The problem demands that you use every piece of data you can from the second and third weighings - you must be able to deduce something different from the scales going down to the left, down to the right or staying the same