hello1997

分3組4隻波子秤; t& L- V3 C- T' G3 p3 j

1 w( ]" z$ k' o1 A6 |' ZGroup A: 1,2,3,43 u3 E5 S6 y2 I
Group B: 5,6,7,8
, U! h, n! `% j) f9 r9 y. YGroup C: 9,10,11,12
3 _+ D" x9 r! ], c5 b. kGroup D: 13% _8 a: ^" |' u3 P0 o' I. U
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Round 1% E! l3 c# Y5 R* n$ N
Group A vs Group B* Y* G- Y/ a' m% {0 d* r
如A and B一樣, 即較輕一粒在Group C or D
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/ s6 S( |5 V& G  q- rRound 2
7 l( S0 i5 F1 _) \再在Group C拆成:
7 }- q4 L3 i0 v7 B! O/ yGroup Ca: 9,102 i- h8 f" I3 L; W+ ?! W# W) ~; T
Group Cb: 11,120 T  F8 d: r+ k0 `
然後再秤, 如一樣, 即13為較輕一粒.
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如不同, 即較輕一組有一粒較輕波子在其中,
) ?+ t6 w! X8 B  f' t要再秤, Round 3, 之後便知答案./ ?* E* z4 y% ^" w  I$ p$ C; b
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e.g. #1 假設10為較輕的一粒6 ~& [. h% G/ Y# c$ f6 `
Round 18 D% m, D5 o+ |6 I' Y# e+ Q, a: p
1,2,3,4 vs 5,6,7,8 = equal1 D- \! Z* G( `5 y6 a) A* A' o6 C
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Round 2$ Y6 o8 _% ^1 f/ o. ^4 v
9,10 vs 11,12 = 9,10 < 11,12
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1 S4 m* ]+ b7 l7 mRound 3' n" d& M* C1 o' j. d  h- d) z: x
9 vs 10 = 9 > 106 L& u8 a5 X( q

; ]" V( f6 B; {; gThe answer is 10.$ P) D# c8 {( R, O8 \1 Q

! \7 x/ P: a5 b! Z( x6 se.g. #2 假設7為較輕的一粒& l6 r) c9 y- h6 O
Round 16 K9 D' S8 S5 O8 s$ @; t
1,2,3,4 vs 5,6,7,8 = 1,2,3,4 > 5,6,7,83 r- E7 P" G7 n

4 a- O" l. M! yRound 2
  ]6 F0 v( [' [( g' C+ n5,6 vs 7,8 = 5,6 > 7,8
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; P0 p0 p9 [; j3 R! ARound 3
0 @7 K7 k! |5 m7 o  D1 g: B7 vs 8 = 7 < 8
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The answer is 7.+ m' _9 d5 o! Q4 X0 `/ U. R

: M1 j! s8 v5 n" x$ P7 Be.g. #3 假設13為較輕的一粒0 h5 U- n  ~: c5 ?' c
Round 1
% ]/ Q6 m9 D, _) u" M" }  X1,2,3,4 vs 5,6,7,8 = equal
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Round 21 y- }% N) I; R  U6 R( P9 v$ u
9,10 vs 11,12 = equal" O+ m! `% E6 m) Y
9 G5 q1 W+ {  v- \& B) t5 K; I
No Round 3" I! K- Q. z% J+ z! T, a% M+ w5 Q4 F

" m7 q5 J* c# c( f2 I, zThe answer is 13.
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唔知我答得正唔正確呢?! 6 q0 u. g& n$ _( J. `& L
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[ Last edited by hello1997 on 2007-3-2 at 12:39 AM ]