hello1997

分3組4隻波子秤3 O# C; J' W: X* @% {1 ^1 U

0 ~9 @4 Z% y2 W1 n# G0 yGroup A: 1,2,3,4+ s, U6 z8 S. [+ K
Group B: 5,6,7,8" l+ E: C- F' R) c# A/ o* d7 f
Group C: 9,10,11,125 Q4 S; C2 \  n, T7 M7 o
Group D: 13( J& u4 M8 `5 F! F* Q0 F8 \8 z# S

$ B  S3 x5 F; j" L$ G; g/ C0 l/ @! ]Round 1
$ G" @6 c7 d7 d% D2 yGroup A vs Group B
) @- F- T4 D/ T+ o如A and B一樣, 即較輕一粒在Group C or D: f( n; V( H* F/ `+ M

: S# u  H( n. d/ a+ jRound 2
2 s, Z0 b, A- [; t( f" H4 N再在Group C拆成:" n7 k& F0 C. f7 P3 ?# O
Group Ca: 9,109 r+ ]. Z! j" ]% q3 a' b; ~
Group Cb: 11,124 [! R1 [! P) ?" w! S: P' x" q
然後再秤, 如一樣, 即13為較輕一粒.9 H4 I( J! F, c! `* K9 Z# m

" ?9 s- v' `+ S! f( F如不同, 即較輕一組有一粒較輕波子在其中, 6 [) A5 z" ?- c7 Q9 V1 ]
要再秤, Round 3, 之後便知答案.
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9 S7 \% f' D; Ke.g. #1 假設10為較輕的一粒
! L3 D: |7 Q, B! t: cRound 1
( n! i5 I# Q5 w1,2,3,4 vs 5,6,7,8 = equal
6 R! E6 B/ m5 {8 P; U" ~" p: N" f7 g6 w* p
Round 2+ D1 V% l0 [3 D3 M3 e+ P
9,10 vs 11,12 = 9,10 < 11,12  y5 |4 c" S& ]

8 Y4 v; M5 f  b. sRound 3% v/ j, Y' h" Z/ A9 D/ W
9 vs 10 = 9 > 10
3 M+ M) s9 T7 |( ?+ H
4 @4 l# I; H% F6 }# JThe answer is 10.$ L. w5 _" w4 j* n7 _- `' [1 ?7 r: E
2 l! U6 U* e4 v
e.g. #2 假設7為較輕的一粒
" j" M5 s! o7 z& K4 wRound 1; Z$ _3 m2 T7 f& N+ o8 k
1,2,3,4 vs 5,6,7,8 = 1,2,3,4 > 5,6,7,8) O' B) n$ W0 u( ~
, k; g: v# b, q
Round 23 M; _0 v. K1 I# x% w+ m+ ]4 v
5,6 vs 7,8 = 5,6 > 7,8* U0 ~0 N& Q8 F2 @* k
6 r, j. A+ N0 s
Round 3! M* [2 k. |8 D/ u( \; j  \
7 vs 8 = 7 < 87 [0 }' o5 _- N7 `2 H
4 p5 q& n+ C5 f
The answer is 7.- C. U/ N) K# M( ~! \$ R

1 B5 L+ T0 D# Ce.g. #3 假設13為較輕的一粒
5 H# f+ C9 e$ b6 c+ `Round 1
6 C- l4 ?( F$ Y% R5 D9 G1,2,3,4 vs 5,6,7,8 = equal3 L0 A& M* ^/ V" A) C9 M3 ^  _2 V
9 e( y7 M$ p8 h
Round 2
3 z  d9 R6 H) ?) _9,10 vs 11,12 = equal9 b  D1 u- e6 N$ Y" z7 W( \
* e5 H! u' ]7 z. K  k
No Round 35 ~4 t( y! M$ [3 O8 y

5 `# u8 c/ b. z$ x6 w0 J+ LThe answer is 13.
7 p$ H( C2 C' p: d5 I6 W, t1 `+ T8 o& a+ g8 P+ D+ v
唔知我答得正唔正確呢?!
5 g3 S$ s  j& E3 N/ `9 W9 z) j" [( R$ M$ H( f+ L0 p/ y0 u  u
[ Last edited by hello1997 on 2007-3-2 at 12:39 AM ]