sitsky

take 4 balls as a group, 3 groups - A B C
7 E! d1 v% \2 t% `6 D. {* ?+ ]' `公仔箱論壇weigh A & B (ex. B heavier)5.39.217.77:88984 z8 y' q$ d8 V3 _2 s/ c
then weigh B & C (B & C same weight)
1 w, E) U3 ^0 \; Y0 Y& G* a" H: Sto find which group has the weight difference and find out is it (A is lighter)# g" N8 Q# t, ]% }; d: N
heavier or lighter4 ^, ?8 \# J) B2 f
then measure 2 vs 2 balls, EF vs GH, pick out the lighter group (EF lighter)公仔箱論壇: |1 Q" ^+ Z. a9 l% }/ J
measure E vs F to find which 1 is lighter....