divde the 12 balls into 3 sets of 4.
1 f: y' _3 Y2 ~, n, l' d& _! Qtvb now,tvbnow,bttvbweight any 2 sets.公仔箱論壇. V4 Q T& U' s5 f
if the 2 sets are equal, then you know the heavy one is in the third" m- h- N2 [2 Y; f+ x# |, j m; @& `7 _$ N
if one of the 2 is heavier, then the heavy one is in that set
# U* ? W' I, E6 pthen divide the 4 balls into 2., q2 B% j' Z8 q
weigh them
9 h) T/ `- x$ _0 o* m- nand divide the heavier into 1
- D9 u3 @" p1 R$ e1 d( Pand weight them.tvb now,tvbnow,bttvb& ^/ [/ k3 P; J9 D/ ]( A, p" ]
3 x weighing and get the ans. 公仔箱論壇$ J1 U* G/ F% \, T. _/ I5 J
in less than 15 secs. |