put 3 balls on each side, tvb now,tvbnow,bttvb' ?( j/ g% \% n- D N+ l
if balance, we can prove that all 6 balls on the 天平 is normal,
! n* w5 n% J, C0 z% H8 @0 K& _- {if not balance, we can prove that the 6 balls outside the 天平 is normal.( p) v4 ~' m! t1 t5 Q
then use the proved-normal ball on one side and put the other ball on other side & Z# `5 \! d6 R2 X
to determine the abnormal is heavy and light |