put 3 balls on each side,
8 M' J( V8 h5 n+ v9 y& ]- |% @4 S: lwww2.tvboxnow.comif balance, we can prove that all 6 balls on the 天平 is normal, ' c7 k+ u) o, j' M. X, D) Q
if not balance, we can prove that the 6 balls outside the 天平 is normal.tvb now,tvbnow,bttvb5 B& u9 g z5 c C! ]! C3 r6 f( _
then use the proved-normal ball on one side and put the other ball on other side
6 f7 {$ J8 r6 k. b- b- | k4 x# `to determine the abnormal is heavy and light |