hello1997

分3組4隻波子秤; q8 z3 k5 Q2 \' m% x  L

' x, g# l* Z  M% aGroup A: 1,2,3,4
% B/ S% M7 y# @  E+ Z4 yGroup B: 5,6,7,89 e$ L8 n) u1 ?1 ~
Group C: 9,10,11,12! t1 m8 w  a( ?  o1 m
Group D: 13
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. R* n3 ^- n- k- j3 y; _2 I+ [Round 1% `$ a% ?/ T% {
Group A vs Group B6 Y2 i8 i- Y  L- J* {' L0 d5 L) p5 [4 {
如A and B一樣, 即較輕一粒在Group C or D) B0 s) s2 a" X& L4 ^* M
1 J+ c6 j' ?& Q2 b$ `- T! W
Round 2
9 P  b; k1 f" e再在Group C拆成:
& J/ `& v5 _4 ^Group Ca: 9,10; p$ L4 o$ g# C5 a4 a
Group Cb: 11,121 J. n" D, M, c) a' I. C' x
然後再秤, 如一樣, 即13為較輕一粒.# G8 Y* s( I* t' J/ j

8 g- _) V) e" r2 N/ F如不同, 即較輕一組有一粒較輕波子在其中,
, I* M# T9 W' V( M' O: a. \要再秤, Round 3, 之後便知答案.7 T3 s4 x. e' Q, H0 d( n. i) }
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e.g. #1 假設10為較輕的一粒( k& @* o, k' \) C
Round 1" c) F2 p. k% g( v! d
1,2,3,4 vs 5,6,7,8 = equal3 H; b: C# o# d* ~; X# N0 b2 r
) `" P( h! C+ a! B
Round 2
$ V* B6 }( ]: G' `# m9,10 vs 11,12 = 9,10 < 11,12' s" w. ?/ O, `, ]0 q& `/ m

4 X: t8 y% w* z1 sRound 33 h# v6 K5 X. l  W0 Q6 o
9 vs 10 = 9 > 10$ f( {2 v' m0 h& N& e
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The answer is 10.
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% x5 {6 f# H; r' p' m% x0 Xe.g. #2 假設7為較輕的一粒  K$ H9 C8 m4 v+ @3 y1 w
Round 1# y3 F0 D: V2 L) s" T- o
1,2,3,4 vs 5,6,7,8 = 1,2,3,4 > 5,6,7,89 t* O& G; M5 w  t# T( [
( d+ U9 o0 k+ l& x2 G2 h8 J# l; T
Round 2
7 q8 d8 }" Z0 X& `5 ~. a5,6 vs 7,8 = 5,6 > 7,80 V! X$ C4 \' ]+ ]3 J
. ]6 {; k  v8 r" c
Round 3
8 ?$ \; M8 l* P- P7 vs 8 = 7 < 81 B8 ^+ H% b* f% O* ]

  z" S% O' c9 n  {" ]) J, j# J% IThe answer is 7.
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e.g. #3 假設13為較輕的一粒
/ x: X+ h- Z+ v0 d! K  hRound 1
) [# d4 I4 }# P/ E1,2,3,4 vs 5,6,7,8 = equal) v9 Q$ C# }( r- G& m8 w& }
9 U5 D# _: M6 o2 k. e- F3 f
Round 2# L, D4 V. `3 ^+ F
9,10 vs 11,12 = equal9 X- d% q$ j1 s) R$ H" n7 i' J! t

6 M; b) W% X. ^) H$ Y$ D' mNo Round 3) w" A( b9 I5 Q6 V6 J( w$ I
' [1 p0 k4 n0 ~4 V
The answer is 13.6 ]& S/ a+ R7 ]) o1 a9 @! X) Q3 c

0 Q& |% |. L9 c5 F$ F$ c7 r4 {唔知我答得正唔正確呢?! ( L: a3 r* p6 N+ K, {# D

; s# l2 Y& L  n[ Last edited by hello1997 on 2007-3-2 at 12:39 AM ]