divde the 12 balls into 3 sets of 4.
$ a l7 S% F; F3 C G: P2 o公仔箱論壇weight any 2 sets.www3.tvboxnow.com4 Z( R" ]- O% p
if the 2 sets are equal, then you know the heavy one is in the third
( { ^1 @, H9 W! P& a/ R( k公仔箱論壇if one of the 2 is heavier, then the heavy one is in that set
& ~4 o; R: e- {then divide the 4 balls into 2.公仔箱論壇9 n% j4 v2 `" y5 j8 @/ v
weigh them4 f" s' w/ Y. b) S6 k: {0 \( B
and divide the heavier into 1
. \! D; p1 z* ?3 U) L9 @公仔箱論壇and weight them./ n7 W2 U9 C! Z, P2 d
3 x weighing and get the ans.
+ ^) r4 V m( O0 btvb now,tvbnow,bttvbin less than 15 secs. |