put 3 balls on each side,
2 }/ v; j1 u7 H- Z$ e7 L+ t* Pif balance, we can prove that all 6 balls on the 天平 is normal, 公仔箱論壇+ B$ e+ j2 D4 A% G
if not balance, we can prove that the 6 balls outside the 天平 is normal.
6 Y: E1 z* s8 C, d& p1 W/ _1 Ethen use the proved-normal ball on one side and put the other ball on other side
3 [* q* T0 {# ]: u* l) Wto determine the abnormal is heavy and light |