i thing the answer is
H5 A! t" u% {: E3 E& l8 [, P- m5.39.217.77start with 4 on each side of the scale,this will have two possible outcome, same or diff.
* B: W4 i6 d' I8 h6 n) DIf 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. |