divde the 12 balls into 3 sets of 4.
0 E2 l S Q7 u; e2 j5.39.217.77weight any 2 sets.
9 v* U, K7 Z+ K+ ]9 x) n* j% q9 Z公仔箱論壇if the 2 sets are equal, then you know the heavy one is in the third
+ l; v2 S! _, xif one of the 2 is heavier, then the heavy one is in that set% e/ ~2 x' h$ Y5 m' Z
then divide the 4 balls into 2.5.39.217.773 w, `5 u, b: S ]
weigh them
/ N; f* s* s8 N5 w' `# _/ x" [5.39.217.77and divide the heavier into 1
+ o6 ~) C5 A8 i7 f! J7 G$ M5.39.217.77and weight them.公仔箱論壇0 A1 C2 M* E5 K2 r/ N$ d
3 x weighing and get the ans. ; }+ m% ^ a y$ d, H- R
in less than 15 secs. |