hello1997

分3組4隻波子秤
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0 j# c. y9 i; |2 @8 P1 b9 @Group A: 1,2,3,43 u- z5 F! ~$ d5 U) ?/ X7 l: O& W
Group B: 5,6,7,8$ d: X: p0 B4 l: q' }$ d" J* Y8 T
Group C: 9,10,11,12& @2 @- i  |3 Q2 ?
Group D: 13$ ~" T+ z. `* c, m
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Round 10 m) Y- q+ x; ~; n% Q  T/ Z1 X
Group A vs Group B0 c) |! D  R! u9 }
如A and B一樣, 即較輕一粒在Group C or D
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5 }/ j/ x, C9 u! R5 L5 T' aRound 27 Z$ w! H1 R# w6 m2 ]8 L8 i2 P
再在Group C拆成:) o1 H% U; H! c& c# Y- k9 K  o( s
Group Ca: 9,10# t/ P6 ]5 i7 l* k8 \
Group Cb: 11,12( r( A, U% P  z; _
然後再秤, 如一樣, 即13為較輕一粒.
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$ ]  K& z$ s- E6 ]2 J$ a. a8 L$ x如不同, 即較輕一組有一粒較輕波子在其中,
6 Z3 a. c3 d+ N: _+ l$ P要再秤, Round 3, 之後便知答案.: U% d1 R$ _) d# N& k% ^" V+ B% z3 k

  m. r+ g9 G( A% q" \3 J, Ne.g. #1 假設10為較輕的一粒5 c# s8 u* H' `
Round 1
* c2 I5 g4 w- \5 u. x! M0 U% S2 [1,2,3,4 vs 5,6,7,8 = equal& ]2 d: W# q/ T' B. I& M

7 p' h8 }  w6 o" @( q+ g) f- ~! DRound 20 G& g9 c) ]3 ]' D
9,10 vs 11,12 = 9,10 < 11,12+ j2 a9 s& I7 i. @; ]- ?: x

( C8 r7 ]  l3 j' VRound 3
& L* h2 A  r3 B- |0 N1 f: l6 Z5 ?9 vs 10 = 9 > 10
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3 A7 p: j9 P+ |4 x+ UThe answer is 10.
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e.g. #2 假設7為較輕的一粒- S2 Z' g7 g% S% J( V
Round 1
2 R: l8 i) h% A/ A" ]# u1,2,3,4 vs 5,6,7,8 = 1,2,3,4 > 5,6,7,8
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Round 2) x# U$ Y. K, t& l9 B
5,6 vs 7,8 = 5,6 > 7,82 j( B5 O4 V! B& U( `" }

- Z7 S1 C/ {  YRound 30 p0 I  b& ]: g% B! f, g
7 vs 8 = 7 < 8
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( ~- W4 a$ ^/ Y- X9 RThe answer is 7.9 R) x! X- Y3 Y+ r3 Q
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e.g. #3 假設13為較輕的一粒
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1,2,3,4 vs 5,6,7,8 = equal
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Round 2# t( V* p( L$ v+ _, E4 G
9,10 vs 11,12 = equal
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$ U0 d; a, b; c4 z+ kNo Round 3. Y! A- S! L% g! `% ?  b6 j2 {

. s! |% R& e- T( L- LThe answer is 13.
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唔知我答得正唔正確呢?!
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[ Last edited by hello1997 on 2007-3-2 at 12:39 AM ]