put 3 balls on each side, os.tvboxnow.com8 o2 J* R: O# W2 z) @. ~# d
if balance, we can prove that all 6 balls on the 天平 is normal, os.tvboxnow.com( }9 p3 {4 G0 L7 |6 P C0 ]7 l1 E
if not balance, we can prove that the 6 balls outside the 天平 is normal.公仔箱論壇4 q) |9 f7 V$ ?' ]/ v3 a8 _" l
then use the proved-normal ball on one side and put the other ball on other side
' }. @: z( t/ ~# g E% Z3 ~# W F公仔箱論壇to determine the abnormal is heavy and light |