divde the 12 balls into 3 sets of 4. * U3 _+ a5 r+ z5 y
weight any 2 sets.tvb now,tvbnow,bttvb0 E# V8 g1 d- Y1 Q& W3 O' U2 c
if the 2 sets are equal, then you know the heavy one is in the third9 H+ _4 K0 L2 H4 y# K
if one of the 2 is heavier, then the heavy one is in that set
. \! K+ ?+ Q% z( R @1 \7 r7 P- p K公仔箱論壇then divide the 4 balls into 2.
" _8 f' S/ @/ F3 d& [weigh them7 ^! x$ A! B ?. \ O o
and divide the heavier into 15.39.217.768 j5 J+ b [# K: E4 U4 W
and weight them.
- Z4 S) T& U7 l+ h! U! {! ?8 c公仔箱論壇3 x weighing and get the ans.
& a7 ^' O7 ` ]3 ytvb now,tvbnow,bttvbin less than 15 secs. |