In Psychology today, we were given Piaget's Twelve Billiard Balls puzzle to sort out. Why? Ask me another. Surely this would be a
Maths problem.
The Twelve Billiard Balls Puzzle
There are twelve billiard balls, all the same size, shape and colour. All weigh exactly the same, except that one ball is slightly different in weight, but not noticeably so in the hand. Moreover, the odd ball might be lighter or heavier than the others.
Your challenge is to discover the odd ball and whether it is lighter or heavier. You must use a beam balance only, and you are restricted to
three weighing operations.
Solution here.