You have an equal-arm balance scale and twelve solid b***s. You are told that one of the b***s has a different weight from all the others, b

You have an equal-arm balance scale and twelve solid b***s. You are told that one of the b***s has a different weight from all the others, but you do not know whether it is lighter or heavier. You can weigh the b***s against each other in the scale balance. Can you find the odd ball and tell if it is lighter or heavier in only three weighings?