Well..divided into 6/6 first to define a heavier group is certainly right. Randomly select 3/3 will result another heavier group. & O0 |3 N% F9 { G公仔箱論壇The 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.6 h* s7 O0 ]! z" ?& d& y; r