first divide it into 3 groups... 4 for each group...
6 g0 N* u% J2 o& O$ c/ ~7 ?9 w+ B公仔箱論壇den use 2 groups to test... if the weight is same... den throw away these 2 groups.. if not... use another 1 group to test with tat 2 groups... throw away the same weight groups...: W) F4 U5 `6 [( l$ j; `
den... left 4 balls...
+ I7 |+ V2 Q% ^8 n" ]" |when u use tat 3 groups to test... u oredi know it is heavier or not...! T2 L; g; M1 q& T# O
so when testing these 4 balls... u juz nit 2 find out the heavier or lighter 1...公仔箱論壇7 M1 J, g' h4 L) q
take the heavier or lighter 1... throw away tat 2 normal ball...
; y% V0 H( X$ L: ^tvb now,tvbnow,bttvbden u juz nit 2 test the last 2 balls...
: q2 I7 i0 i& R* E- Etvb now,tvbnow,bttvbsame for now... take the heavier or lighter 1... |