put 3 balls on each side, - g7 F9 K. [: B# Y( D! w, M
if balance, we can prove that all 6 balls on the 天平 is normal, . d- |7 I+ T( \7 |& q1 O `, ^
if not balance, we can prove that the 6 balls outside the 天平 is normal.
" t5 B; [( n' C, P, J2 rtvb now,tvbnow,bttvbthen use the proved-normal ball on one side and put the other ball on other side
7 o# S+ A# F- p+ P2 uto determine the abnormal is heavy and light |