12 Marbles

You have one balance and 12 identical marbles. One of the marbles is a different weight than the rest (either lighter or heavier). You must do two things to solve this puzzle:

You have 3 weighs of the balance to determine which of the 12 balls is different than the others. With this information you must also
determine whether the marble is lighter or heavier than the rest.
Submitted  3/24/2000 9:52:01 PM
Hint   Answer