ceteriz

divde the 12 balls into 3 sets of 4.
% _! R; O* Q. P( h6 p公仔箱論壇weight any 2 sets.
# @1 c6 j3 P# o5.39.217.77:8898if the 2 sets are equal, then you know the heavy one is in the third
) ]# p1 r2 S8 E/ a5.39.217.77:8898if one of the 2 is heavier, then the heavy one is in that set
0 v; o7 t, t  F, Z, A# X, ^$ h- u4 _. Wthen divide the 4 balls into 2.
+ e! H2 v. G1 G5.39.217.77:8898weigh themTVBNOW 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。) L9 P# o7 h# h% {/ p
and divide the heavier into 15.39.217.77:8898' l: X5 L- Z  C" s6 ~8 O' t
and weight them.
/ o( M$ e7 s# Jtvb now,tvbnow,bttvb3 x weighing and get the ans.  公仔箱論壇  v  Q- e+ l- ]/ I/ x6 d) Z; _
in less than 15 secs.