divde the 12 balls into 3 sets of 4.
5 ]4 k) @: x; u9 I: y C" U+ ]$ U6 w5 rweight any 2 sets.
- e" W+ X2 `% z; P' P. a公仔箱論壇if the 2 sets are equal, then you know the heavy one is in the third公仔箱論壇/ b" ]2 j/ U' C8 `0 u: |# [
if one of the 2 is heavier, then the heavy one is in that set/ K! p. o- b; i2 K# B) U/ g
then divide the 4 balls into 2.公仔箱論壇& q8 ]# T4 j8 Y, w+ X! r$ g
weigh them
0 f# Q8 L9 p% t7 T. d$ {: Gand divide the heavier into 1
1 U4 D+ f5 l0 H公仔箱論壇and weight them.tvb now,tvbnow,bttvb+ u! ?! \9 l) d; j' L/ V
3 x weighing and get the ans.
M* p+ c* [' Otvb now,tvbnow,bttvbin less than 15 secs. |