put 3 balls on each side,
3 z* G, w) P+ D3 V6 F4 K公仔箱論壇if balance, we can prove that all 6 balls on the 天平 is normal, tvb now,tvbnow,bttvb* L6 [# l% Q* l M
if not balance, we can prove that the 6 balls outside the 天平 is normal.* Q. s2 {, L( p" J" h9 b6 @" |* i
then use the proved-normal ball on one side and put the other ball on other side
6 g3 B* A- Z* Uto determine the abnormal is heavy and light |