Put all 12 balls on the weighing balance, get the total weight,
then take out each ball from the weighing balance one at a
time.
By doing so, you will be able to get the weight of each removed
balls from the weight difference in the before removing and after
removing each balls.
So you will be able to know which ball weigh different from the
rest.
But why need to use the weight balance for more than 3 times? 1
time enough le......
By weighing balance, I meant a non electronic scale (imagine the
see-saw)
And also, by removing any ball from the balance, it
automatically counted as another usage on the balance.
