i thing the answer is公仔箱論壇" c6 W5 O$ q2 l9 l
start with 4 on each side of the scale,this will have two possible outcome, same or diff.
. p6 u2 r6 Q: z1 g0 j: g9 G# r# `0 KIf 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. |