i found the ans in 30 mins but dont know correct or not?tvb now,tvbnow,bttvb8 c: F" y I d: h* h( m; n( L" {
ans is too long! but concepts are something like that:
9 E# q# n, `8 z8 K& A; jseprate 4 groups 3 balls in one group! 公仔箱論壇9 C7 z% g+ [5 \% Z9 @- _
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!
+ p4 E1 I) B3 @( I7 L& ~- pthe last part is 1ball vs 1ball! something like that |