put 3 balls on each side, : X2 Y% a; \% ]: T6 ]9 U
if balance, we can prove that all 6 balls on the 天平 is normal, 9 m. w- r8 {+ {. ?4 _" y. Q
if not balance, we can prove that the 6 balls outside the 天平 is normal.
& K8 b3 C) d7 @- O: w) T2 ^, S公仔箱論壇then use the proved-normal ball on one side and put the other ball on other side
! n# w) d [' uto determine the abnormal is heavy and light |