1. 1st divide to half take the heavier out & X: u9 I% U! k9 a$ o/ I6 x7 P公仔箱論壇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) 3 M- B% J5 e% q4 v8 ]3 S& C- V* e# otvb now,tvbnow,bttvb3. Same method if is not equal on 2nd try.