gensy850711

first divide it into 3 groups... 4 for each group...5.39.217.76" t7 |4 Q7 C6 C, k9 R
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...0 {2 D2 o7 ]* f5 T) G4 W- X
den... left 4 balls...
6 N3 I! a! t# x$ i% ]when u use tat 3 groups to test... u oredi know it is heavier or not...) X% Z5 Y& ^+ _
so when testing these 4 balls... u juz nit 2 find out the heavier or lighter 1...
/ p/ @) a# q6 I) E! y: o& g! Y- qtake the heavier or lighter 1... throw away tat 2 normal ball.../ w  x' @' s. `* A/ T
den u juz nit 2 test the last 2 balls...5.39.217.766 k  q! e* t& W; M" h: K1 o, `: s% K) K
same for now... take the heavier or lighter 1...