i found the ans in 30 mins but dont know correct or not?公仔箱論壇) E% V( Y. Z: z8 x& D- C+ s
ans is too long! but concepts are something like that:
3 U; ^* T: O+ B4 q* e- ?6 j4 Zseprate 4 groups 3 balls in one group! 7 ]# {* H, p% W
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!
, n' \: w+ ^7 E/ e! Ntvb now,tvbnow,bttvbthe last part is 1ball vs 1ball! something like that |