i found the ans in 30 mins but dont know correct or not?公仔箱論壇! M+ B+ V9 L. B+ q2 R9 ^& y0 u
ans is too long! but concepts are something like that:
8 F9 w* f$ |6 Ptvb now,tvbnow,bttvbseprate 4 groups 3 balls in one group! - U1 O3 C0 J+ z- F; Q
the important part is the 2nd times which need to find out the fake ball is heavier or lighter by use the normal ball that u find at the first time!
3 L9 M5 n: T! n" itvb now,tvbnow,bttvbthe last part is 1ball vs 1ball! something like that |