>You have 12 billiard balls.
>
>One of them is either lighter or heavier than the others.
>
>You can weigh the billiard balls 3 times on a balance scale.
>
>You need to find out which ball it is and whether it is heaver or lighter.
Here is a similar problem:
There are 6 balls: 2 red, 2 blue and 2 white. One of the balls of each color is slightly lighter than the second ball of the same color (you can name these two weighs as A & B). You need to sort out all the balls. You can weigh them only 2 times on a balance scale.
If it's not broken, fix it until it is.
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