hello1997

分3組4隻波子秤6 m6 d% u( ?( O3 e1 V

$ ^5 m  X, O8 q$ }$ H5 B: o3 P( LGroup A: 1,2,3,4- g  y; {1 `; c* m- z
Group B: 5,6,7,8
8 b$ r7 r# Y" D. fGroup C: 9,10,11,121 m/ k5 f9 ]. c$ ~7 X7 V
Group D: 13! r8 F: L6 J- x, V& y6 V4 ^/ H

* s7 z/ n9 m& c1 o$ Q/ W% u$ z5 uRound 1
2 \5 E/ a2 ]& a* ~, KGroup A vs Group B7 w/ I4 s7 }' [( E6 a3 d* x' I
如A and B一樣, 即較輕一粒在Group C or D# h! ^1 t% `7 ^0 |" _: h5 r$ v
" A+ j  X( b  d, o; S+ I7 k
Round 2
9 N) D9 e7 B' k, k, H3 n再在Group C拆成:0 N, I# M7 Q, `1 R; m! D
Group Ca: 9,10+ v, d6 `1 f8 Z0 H! c9 d# a. s6 ~
Group Cb: 11,121 B! O( f. G1 c+ P" H9 j
然後再秤, 如一樣, 即13為較輕一粒.7 Y$ R; o2 a! I/ f% x
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如不同, 即較輕一組有一粒較輕波子在其中,
; ?7 @7 o% L5 S9 c要再秤, Round 3, 之後便知答案.
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e.g. #1 假設10為較輕的一粒0 z; J/ `: o. h
Round 1
) {0 E9 j' j  c0 M: F6 c# r: ~3 ]2 e1,2,3,4 vs 5,6,7,8 = equal
" ^# X  c9 |1 U# m7 ~5 ?
6 t) a$ \/ p0 l  F0 B: f3 URound 2  M1 D9 `. R: V8 [0 q0 F
9,10 vs 11,12 = 9,10 < 11,12
8 Z& ~& K; l8 ?$ @, E, G3 t  y' Y; V" `$ F
Round 3
! w2 H  _& _  e/ ~9 vs 10 = 9 > 10
3 n0 m3 i- l' H* D9 x4 n+ }" D0 o8 s; I. p$ C; e- A! i
The answer is 10.
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& V+ M" Y! O% {# x) s" ne.g. #2 假設7為較輕的一粒8 e, P; C0 D. B( x5 v  {1 q
Round 15 |% |: J) U9 |
1,2,3,4 vs 5,6,7,8 = 1,2,3,4 > 5,6,7,8
( d: s0 q7 i. v  r$ }" y% v% W! U6 A- t5 r) B3 q; ?/ n/ L( N0 _2 E% }
Round 2
6 y/ F$ `+ k  }7 E  N5,6 vs 7,8 = 5,6 > 7,8
4 H+ U0 m3 O7 [
6 E0 ^; b  R) r# WRound 3
- R* R3 E5 G5 `& m! E( q7 vs 8 = 7 < 8, @3 I9 n1 A' v! _; p0 _
7 `  Y3 g( U9 q7 f$ ?
The answer is 7.+ {" [& I( d: P: H9 v
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e.g. #3 假設13為較輕的一粒8 e) O  c3 E% N, f2 D
Round 1( f1 x7 h! h$ ?. z* n/ R
1,2,3,4 vs 5,6,7,8 = equal
+ O1 c& P( W  d; O6 t8 X
5 A* s$ }/ `3 r. ~0 R. kRound 2$ A8 b* A7 S" K8 M+ D
9,10 vs 11,12 = equal
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No Round 3& f! |- a0 H; l# Z
4 k( I4 d0 l' o) J
The answer is 13., B9 K! x2 L; q! _* n' r& t' b

! t  ^' m9 U) a, m唔知我答得正唔正確呢?!
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/ [- k$ i& s2 v0 J$ w[ Last edited by hello1997 on 2007-3-2 at 12:39 AM ]