hello1997

分3組4隻波子秤
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* \9 }$ w& L, E% TGroup A: 1,2,3,46 \* C2 J" t5 Y
Group B: 5,6,7,85 d+ V* L; p% U" y
Group C: 9,10,11,12
6 ^+ U4 D3 z6 Q- S4 w. R) PGroup D: 13& ^9 \$ B1 [& R

: i/ e6 o. S! BRound 1" y6 s6 a) m+ D5 ?0 g  r
Group A vs Group B. {7 |( E# ?8 Q$ B4 ^" h  b$ K. J
如A and B一樣, 即較輕一粒在Group C or D$ H. \9 Y# y6 b- d( V6 Y5 q4 n8 A

4 e0 m+ ~  S  M; q- nRound 2" f1 i! f" s* w6 X8 Q
再在Group C拆成:% G5 J( h  N8 p2 B
Group Ca: 9,10  d; r) M$ \: j* X) A7 l$ O
Group Cb: 11,12! o  {+ o( s/ Q- F6 M3 L! w
然後再秤, 如一樣, 即13為較輕一粒.
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# K8 I9 h  G9 w* j9 e如不同, 即較輕一組有一粒較輕波子在其中, ( Y; Q: X$ N) C: `* I& R3 v6 h( q
要再秤, Round 3, 之後便知答案.  e; |% _7 M' L* Q( C7 }1 p
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e.g. #1 假設10為較輕的一粒1 Y; w3 B6 k2 G2 ?$ h! y! O' x
Round 1
$ _- S( |+ ]" Z, {  ?1,2,3,4 vs 5,6,7,8 = equal
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Round 2
, j, O$ H& ^+ g6 F+ a& c! w9,10 vs 11,12 = 9,10 < 11,12) U" M" _, ~) m, u+ r4 o

( J8 U- l, _5 DRound 3
& p( L5 E+ _! _" O9 vs 10 = 9 > 10
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' x8 B* M% R* m6 k5 T8 ?The answer is 10.
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( J6 K1 u% Z' w' W/ ]e.g. #2 假設7為較輕的一粒7 r8 p+ y. L% h9 o; I
Round 1' A: y8 \- T" f1 X2 c; d1 v
1,2,3,4 vs 5,6,7,8 = 1,2,3,4 > 5,6,7,82 H* ~1 D- F/ U
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Round 2" h% |3 s( }9 J0 R7 H! i
5,6 vs 7,8 = 5,6 > 7,8
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Round 3  v+ G, \) w% U" J
7 vs 8 = 7 < 8- e/ }- @  Q; B1 {& p

. `! ]0 @, u7 |# ^The answer is 7.
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e.g. #3 假設13為較輕的一粒( ]) m5 I" K/ _3 H% U" g( C
Round 15 I% u' @" P% p, J+ Y+ Q! q
1,2,3,4 vs 5,6,7,8 = equal% ?6 S/ F7 i+ ^' u

) M1 y' A4 s& c2 j5 b" f+ ]Round 2- Z8 L4 k" k- T8 a8 |( s" K
9,10 vs 11,12 = equal, L& e1 z( L# L6 ?! i! u7 e
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No Round 3( z4 Q  C9 @0 ~. d/ Z
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The answer is 13.. l" y$ b  v/ B+ y- \

' Z, z3 ~5 m7 ]9 f0 [  Q+ u2 s唔知我答得正唔正確呢?! * w8 K5 y; d0 d& s, T- x) Q

- S" u) p/ f8 t6 O8 N[ Last edited by hello1997 on 2007-3-2 at 12:39 AM ]