put 3 balls on each side, tvb now,tvbnow,bttvb5 Y9 P. U N7 D/ b% w' @
if balance, we can prove that all 6 balls on the 天平 is normal, 6 w; p3 [' T1 m9 [+ c! Z
if not balance, we can prove that the 6 balls outside the 天平 is normal. F5 ~& U# p- a, Y; t7 c" N
then use the proved-normal ball on one side and put the other ball on other side
9 b }5 Q& r* X \to determine the abnormal is heavy and light |
發表於 2011-5-11 04:50 AM
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