divde the 12 balls into 3 sets of 4. $ N1 n9 y5 N9 F& L! h; ^. k
weight any 2 sets.
% z" }0 }; N6 W/ B( p$ E# R; }' X公仔箱論壇if the 2 sets are equal, then you know the heavy one is in the third7 L& }( l) M* |* _6 H
if one of the 2 is heavier, then the heavy one is in that settvb now,tvbnow,bttvb& }3 S0 ]1 Q4 r/ E6 W
then divide the 4 balls into 2.tvb now,tvbnow,bttvb) O# u0 `: Q. C. Q1 P, r+ l
weigh them
: H' e- x- f5 B9 H7 k公仔箱論壇and divide the heavier into 1
5 u( x/ a+ k: ~' m8 x5 X0 ]tvb now,tvbnow,bttvband weight them.
1 }0 G8 ?, O& g3 x weighing and get the ans.
. o5 t6 M! V2 j8 atvb now,tvbnow,bttvbin less than 15 secs. |