first divide it into 3 groups... 4 for each group...公仔箱論壇4 `+ N1 t: w& Q" u1 A1 x1 v" i$ N
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...公仔箱論壇) G. c) ?+ `) T R1 j9 c& t
den... left 4 balls...
, N' Z) t- _, p& _* `. lwhen u use tat 3 groups to test... u oredi know it is heavier or not...公仔箱論壇- W2 t1 k/ |) Y5 [ c1 |- ]4 M$ P
so when testing these 4 balls... u juz nit 2 find out the heavier or lighter 1...
# Y% w2 ?& c- m# j" r# \. Qtvb now,tvbnow,bttvbtake the heavier or lighter 1... throw away tat 2 normal ball...
. t- s. {2 D. g8 {4 H2 stvb now,tvbnow,bttvbden u juz nit 2 test the last 2 balls...& z$ m# K1 j% o ^6 s$ r
same for now... take the heavier or lighter 1... |