put 3 balls on each side,
8 r/ Q- a* h% h" \5.39.217.76if balance, we can prove that all 6 balls on the 天平 is normal,
1 ?, H- U7 R+ G4 S+ g% d; W! X" Xif not balance, we can prove that the 6 balls outside the 天平 is normal.
6 v, d8 w- l5 q& H" Zthen use the proved-normal ball on one side and put the other ball on other side
& a @1 D/ Z3 M6 K5 E$ L2 c# kto determine the abnormal is heavy and light |