hello1997

分3組4隻波子秤8 q1 \! @  x& f  j2 j

: j( z0 k3 C* R6 V2 y" F# h; \Group A: 1,2,3,4- Z0 Z2 \* ^0 I
Group B: 5,6,7,83 e- [: f6 T/ G; u
Group C: 9,10,11,12
  E! o  P+ [5 P- @Group D: 138 v* |4 Z9 C0 E3 U  G' f8 J! I. l

2 W0 I! D! J, `. bRound 1% j' e- e. x0 Z
Group A vs Group B  n; p8 ?# j% F, J' W! V
如A and B一樣, 即較輕一粒在Group C or D- ~0 n* ]- p. Z4 \6 E7 o( W- C

8 _0 M. S9 v6 V( k$ FRound 2% Y7 {$ c- l) S2 M
再在Group C拆成:5 D7 T# t; Y( x$ U1 p/ _
Group Ca: 9,10
3 A! @, T; z9 c% S% gGroup Cb: 11,12
% f9 Y* K+ n. L! c4 m/ [% F- V/ ]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,   h8 \9 {3 S7 h" w! M
要再秤, Round 3, 之後便知答案.
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2 |0 W) @7 N. h7 M8 B9 b: B; s6 xe.g. #1 假設10為較輕的一粒3 y$ ]. A4 Q; I( g7 ~
Round 1
! [7 _  C$ ~. k1,2,3,4 vs 5,6,7,8 = equal
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' Q# e- _) d4 B  }0 r8 FRound 2
2 J5 N6 {& Q6 D. X0 P+ P, E  B9,10 vs 11,12 = 9,10 < 11,12
0 ^6 l+ H6 i, C: u4 I/ P" |. a
( |' \* H. A+ uRound 3' T, i2 N: p* O$ V
9 vs 10 = 9 > 10$ l' O: h+ o' g+ Q9 M

% S7 l8 l) ^+ }# s1 E6 t1 [7 \The answer is 10.+ m7 ~4 r% z$ y
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e.g. #2 假設7為較輕的一粒
% S: f' K+ w" E+ ~; \& yRound 1' y; g# r# z  U1 I4 Q! ]$ {/ n( Z) M3 z
1,2,3,4 vs 5,6,7,8 = 1,2,3,4 > 5,6,7,8+ j$ \5 Z* O) m  t$ M8 \, D$ R
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Round 2
+ q0 F5 x& @' B. B; o5,6 vs 7,8 = 5,6 > 7,8
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Round 3/ z3 ]% V" G+ s
7 vs 8 = 7 < 8
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3 L  I& B8 L/ I% h" Z) q- x6 [The answer is 7.; W% s  n- a* t0 e
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e.g. #3 假設13為較輕的一粒; ~* R5 J! A7 K$ ^3 l6 x1 a
Round 1( [! ~: L/ o) i$ t: h
1,2,3,4 vs 5,6,7,8 = equal
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Round 2
* ?9 H/ n# _- I+ f# B0 i, G9,10 vs 11,12 = equal
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, |! O; I& |9 B. p1 f! uNo Round 3& r3 b- ~: V- Z# U+ r8 b: n
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The answer is 13.
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0 z! \' ]# K9 L) u# n  d  V$ v唔知我答得正唔正確呢?! 2 N; V, f4 z/ X5 s$ H$ `! x% Z
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[ Last edited by hello1997 on 2007-3-2 at 12:39 AM ]