Well..divided into 6/6 first to define a heavier group is certainly right. Randomly select 3/3 will result another heavier group.
$ I& ~5 [* M' W, \# [" n* y! yThe problem is we don't know the weight of each individual ball, so it will not be accurate to figure out which ball is irregular by only weight them once.公仔箱論壇; p; y" _$ e5 u. ?, D
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