put 3 balls on each side,
$ I( S/ e$ f z+ d+ r( l" h' [tvb now,tvbnow,bttvbif balance, we can prove that all 6 balls on the 天平 is normal, & s5 D$ [) ]8 w$ k/ `% w
if not balance, we can prove that the 6 balls outside the 天平 is normal.% F4 j. C' [4 ]( [! ?4 g6 e
then use the proved-normal ball on one side and put the other ball on other side ( [ F. B& U/ Q$ R
to determine the abnormal is heavy and light |