ceteriz

divde the 12 balls into 3 sets of 4. 5.39.217.77:88982 G' `$ s# f+ j1 |$ u" r- d
weight any 2 sets.
, b! e: m0 U# O$ p! ]1 lTVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。if the 2 sets are equal, then you know the heavy one is in the third5 K  t" m) O5 @1 e" L2 x9 m+ Q
if one of the 2 is heavier, then the heavy one is in that set
5 S  }; W) I$ \' w1 Nthen divide the 4 balls into 2.公仔箱論壇* L; l3 b# [0 C  e+ n2 t
weigh them
- B5 \5 r3 X3 Sand divide the heavier into 1
$ H7 T1 M7 @4 @& k. r# J$ i% }and weight them.公仔箱論壇7 H6 |# L! O* p
3 x weighing and get the ans.  公仔箱論壇  @' d- P  `; h6 U, }/ N9 h
in less than 15 secs.