1. 1st divide to half take the heavier out公仔箱論壇: f7 \2 w _9 H) O1 Q6 i& Z
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) ' m& C9 i7 n+ a3. Same method if is not equal on 2nd try.