hello1997

分3組4隻波子秤) j/ P/ }. k6 R! C5 q4 M7 ?! b4 J
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Group A: 1,2,3,4
- [3 X- Q, I7 E) t8 V; B9 s# k/ OGroup B: 5,6,7,8
* g& A; t0 C+ z+ g5 k& OGroup C: 9,10,11,12
+ [$ H1 ^+ I) L% C' eGroup D: 13
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! J6 d0 R4 D! A8 Y' o% [$ W" q2 o- cRound 1
' a& Y$ s, D5 f) O- w7 oGroup A vs Group B
# j+ H: O6 P$ F. a5 E如A and B一樣, 即較輕一粒在Group C or D3 {6 |% v6 f! o
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Round 25 N9 p/ |$ m; g7 s% o* `2 u
再在Group C拆成:
! O+ {# q% g: Y1 |, yGroup Ca: 9,10
% ?' O6 m1 O6 v" y, v3 oGroup Cb: 11,12% s, |0 D7 {+ N. }
然後再秤, 如一樣, 即13為較輕一粒.% Q8 T( I" z  \3 }& `, P

0 ]; O8 O7 u  y3 A" L如不同, 即較輕一組有一粒較輕波子在其中, ) R& y: w0 D3 M
要再秤, Round 3, 之後便知答案.
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& q3 U1 W+ N, y: M' _4 m$ fe.g. #1 假設10為較輕的一粒$ D% R+ h% s" H3 k+ `
Round 1
. k( w7 }9 P! s. O$ l1 t" [1,2,3,4 vs 5,6,7,8 = equal7 @2 y4 [; N3 {; Q# c

; z( A+ r0 n4 _Round 2" d* _" ~3 i- P% i
9,10 vs 11,12 = 9,10 < 11,12
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: G' [% D% g6 L* e0 Z& R8 T/ V& FRound 3% E3 d( r- j, h0 K% y0 C
9 vs 10 = 9 > 10: J# |9 s6 }  k: j  Y& |# ~2 |

8 [6 h8 r' ]" o# `7 m9 S; ZThe answer is 10.  Q7 _5 l2 |/ v8 E% ]2 O; Z! u

' e  Z5 I" N( U, q1 M0 N( Re.g. #2 假設7為較輕的一粒
" O: q3 y6 D1 \7 r: H7 L9 d$ uRound 1
' L% I( r4 Z" h' i1,2,3,4 vs 5,6,7,8 = 1,2,3,4 > 5,6,7,8
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Round 21 Z0 H4 P: U9 w
5,6 vs 7,8 = 5,6 > 7,8: G0 q; L# t; z- h8 u

, r. @) J% e/ w  j$ d6 JRound 3
0 I. \; {; ^' \) _/ i7 d5 {7 vs 8 = 7 < 8
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The answer is 7.
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8 Z" m0 Y) |, N3 a/ X- |" }8 Oe.g. #3 假設13為較輕的一粒8 V8 Q, M" Z' l
Round 19 {1 X9 I/ Q' k3 f/ A$ X3 T2 ~
1,2,3,4 vs 5,6,7,8 = equal" u5 t! H; z: i% p5 h  w

' ]& J+ R- j7 K. g# QRound 2
# J1 h; F# W  _' X8 B: b# u" J$ h9 g( _9,10 vs 11,12 = equal# ~/ f; B* C) y9 ]* ]. l* H4 C
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No Round 3
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The answer is 13.  [" s& E) \+ p2 j3 j

# N# s; a$ R8 c6 j4 k2 K唔知我答得正唔正確呢?!
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9 w  R: d0 R5 L4 y[ Last edited by hello1997 on 2007-3-2 at 12:39 AM ]