Divide the 12 balls into 4 groups of 3's.% _6 }$ n# R( D- ?) Z- g$ L4 [* X
Weigh group 1 & 29 {: ]! y6 y% Q+ J
then weigh group 2 & 35.39.217.771 d' x; c8 j9 g: X
If the results are Equal & Equal, it means the ball with the different weight is in group 4., q/ f6 x, w* \& D& c+ G
If the results are Equal & Unequal, it means the ball is in group 3.4 `+ ?% c1 J8 o& j# H; u) R
If the results are Unequal & Equal, it means the ball is in group 1.公仔箱論壇( M2 [& E" x- {0 x% C
If the results are Unequal & Unequal, it means the ball is in group 2.5.39.217.77# [1 z3 n3 B. y! s& r/ g
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Once you determine the group that contains the ball. ' s$ |' w$ P/ v7 B1 u( Y7 D! ?tvb now,tvbnow,bttvbSimply weigh two of the balls