1. 1st divide to half take the heavier out) N9 x$ F0 a* u- H
2. 2nd take 4 balls out of 5 divide 2 groups to get the heavier out. (if is equal thn the remain is the one u looking for)公仔箱論壇/ i1 e9 [0 T+ R" f! o H6 `: _; S( g
3. Same method if is not equal on 2nd try.