| 發布者 | 內容列 |
孫文先
Moderator
註冊日: 2002-07-30
發表數: 1094
|  Re: 一個天平的問題 |  | 先減少金幣數學，從2, 3, 4, ....開始探索，再設法歸納。
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孫文先 敬上
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| 2006-06-20 19:18 |   |
fuyaen
Just can't stay away
註冊日: 2006-05-30
發表數: 84
| | Re: 一個天平的問題 | | 基本上這種題目都差不多吧
要一次分成三堆
所以一次可以淘汰三分之二 |
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| 2006-06-20 21:17 |  |
訪客
| | Re: 一個天平的問題 | | 如果要保証一定找到的話
應該是七次 |
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| 2006-06-23 09:00 | |
訪客
|  Re: 一個天平的問題 | | 1000/2=500...1次
500/2=250....2次
250/2=125...3次
125-1=124,124/2=62....4次(若相等,則扣掉的就是假的),62/2=31...5次,31-1=30,30/2=15...6次,15-1=14,14/2=7...7次7-1=6,6/2=3...8次3-1=2,2/2=1....9次...............9次 |
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| 2006-08-15 21:14 | |
孫文先
Moderator
註冊日: 2002-07-30
發表數: 1094
| | Re: 一個天平的問題 | | 再給兩個天平問題
1. You have nine coins whose total weight is 9. Each individual coin has
weight 0, 1 or 2. Using a balance, what is the minimum number of weightings needed to sort the coins out by weight?
2. You have nine coins seven of which weigh the same. Of the other two coins, one is heavier and one is lighter than any of the seven. Using a balance, what is the minimum number of weightings needed to determine whether the total weight of these other two coins is greater than, equal to or less than the total weight of two of the other seven coins?
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孫文先 敬上
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| 2006-08-17 14:59 | |
訪客
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| 2006-08-17 15:38 | |
j7631103
Home away from home
註冊日: 2005-03-06
發表數: 490
| | Re: 一個天平的問題 | | 這類型的題目就像計算類的天平題目,不知輕重比較難,答案確定是7次 |
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| 2006-08-17 17:41 | |
孫文先
Moderator
註冊日: 2002-07-30
發表數: 1094
| | Re: 一個天平的問題 | |
與其他種二幣比較，它的重量趨近於零，可忽略不計。
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孫文先 敬上
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| 2006-08-17 20:04 | |
訪客
| | Re: 一個天平的問題 | | thank you! |
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| 2006-08-21 00:00 | |
