hello1997

分3組4隻波子秤/ r& \4 L" M9 m$ J% m" |

4 b# R, X  [) c9 c: @' ?6 P3 iGroup A: 1,2,3,4! Y# T- s0 E: R) X- y
Group B: 5,6,7,8
5 ]; t' P- R) BGroup C: 9,10,11,125 ~" z/ ^5 Z- S8 o+ W
Group D: 13
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- Z4 z; E* m* lRound 1# X  T  |2 A" u6 Z: u+ l
Group A vs Group B
6 e4 s6 R, M: p: x, c- a; k* f9 ^如A and B一樣, 即較輕一粒在Group C or D
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' n& p/ u, H% yRound 2
% i! ^0 K6 H& c! q4 k再在Group C拆成:
* j, T5 M% P7 }# c9 |# HGroup Ca: 9,10
7 U/ G% R: ]5 _2 ]* X% L: @* qGroup Cb: 11,12& l, z+ _- ~" y; f
然後再秤, 如一樣, 即13為較輕一粒.0 Y9 T3 a& k8 z# S9 x
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如不同, 即較輕一組有一粒較輕波子在其中, 4 ~1 |- k! ?8 d/ M3 K0 z
要再秤, Round 3, 之後便知答案.6 p5 |' U: }3 f4 d: B3 f
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e.g. #1 假設10為較輕的一粒5 E0 r" w4 m1 x6 H( q
Round 1
; w7 E; q" O& a5 i- l" u' C* f- h# t1,2,3,4 vs 5,6,7,8 = equal
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  G6 r# }" I, J" s, A5 q4 F8 lRound 20 E* U1 [- ^9 E; N* |: [
9,10 vs 11,12 = 9,10 < 11,12
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! o. s4 |  e% b+ b! [" R( yRound 3
' @2 _+ p7 Y) W0 c9 vs 10 = 9 > 108 Q: a1 V7 ~, a* v: U1 [
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The answer is 10.
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e.g. #2 假設7為較輕的一粒; F, {" p+ O& t: C, p$ L
Round 1
# b  F6 Y7 Q$ o: D# Y1,2,3,4 vs 5,6,7,8 = 1,2,3,4 > 5,6,7,8$ G( p5 ~- F) j

4 z# T/ R) G6 i3 v+ W- O; w, s  `Round 2
) t0 v/ L3 v' I- ?  V  Y5,6 vs 7,8 = 5,6 > 7,88 ^: ?. n% f2 w0 P: f% }7 {, z

! T* S( u; B2 t( K* G/ y3 ]' rRound 3
+ t" b% ^% w9 O7 vs 8 = 7 < 8
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The answer is 7.& }( \. l$ q0 t
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e.g. #3 假設13為較輕的一粒
* c3 o; g* C& S  n4 _- IRound 1
$ ^3 {2 c9 W. F1,2,3,4 vs 5,6,7,8 = equal8 w; j- {4 g) B  o
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Round 2  L: y( N  y" u: }
9,10 vs 11,12 = equal
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1 @, L2 i; S2 V# P' l. XNo Round 3- }0 u: K% H0 r" ?. c  h0 |2 d

; @+ e2 q( M4 c* d6 NThe answer is 13.
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" ]( `- H% `: F6 X唔知我答得正唔正確呢?! : f$ ~  u4 e5 S' L

; ~- e! A2 P* x- q' `5 g- Z8 Q4 _[ Last edited by hello1997 on 2007-3-2 at 12:39 AM ]