i thing the answer is- Z3 f1 _4 V0 x/ d
start with 4 on each side of the scale,this will have two possible outcome, same or diff.
, W3 M% j' Y E/ M% T7 X: I' t* FIf the same then 4 that left over contain the odd ball. put 1 of the 4 to each side, two outcome, same or different again. Replace 1 from the remaining, if the same then left over is the odd or if different the replacement is the odd one. I didn't time myself but I think I take less than 30 minutes. There are two more possible out come but still need three weighing but I think I am running out of space. |