The marbles riddle

After the success of the riddle about the two mathematicians, here’s another little
gem. Read the problem carefully. This one is a beauty.

We have twelve marbles. One weighs more or less than the others. Can you
find the marble that weighs a different amount using a balance scale and just three weighings?

A balance scale is the same kind of scale they used to weigh Dorota Máchalová in hell.

July 7, 2004 — Solutions added

• My solution
• Yuhůů
• Petr Weida
• Jirka Novotný