i thing the answer is
6 y$ c' A4 Q6 a( B9 `5.39.217.77:8898start with 4 on each side of the scale,this will have two possible outcome, same or diff.
1 m, f. d3 R6 C. `8 b1 ]公仔箱論壇If 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. |