# 查看完整版本 : possibility

poiuy1201 2014-11-22 12:30 AM

## possibility

[size=12pt]In a library, 9 of 10 different books are selected and arranged on a bookshelf. Find the number of arrangement if[/size][size=12.0pt] [/size]

[size=12pt]1) the books with the smallest and the largest serial numbers among the 10 books are put on [/size][size=12pt]the left and right ends respectively.[/size]
[size=12.0pt] [/size]
[size=12.0pt]2) the books with the smallest and the largest serial numbers among the 9 selected books are put on the left and right ends respectively.[/size]
[size=12.0pt] [/size]
[size=12.0pt]Thank you very much!!!!!![/size]

[[i] 本帖最後由 poiuy1201 於 2014-11-22 12:40 AM 編輯 [/i]]

[7] 2014-11-22 06:34 AM

[quote]原帖由 [i]poiuy1201[/i] 於 2014-11-22 12:30 AM 發表 [url=http://www.discuss.com.hk/redirect.php?goto=findpost&pid=402997448&ptid=24052411][img]http://www.discuss.com.hk/images/common/back.gif[/img][/url]

In a library, 9 of 10 different books are selected and arranged on a bookshelf. Find the number of arrangement if

1) the books with the smallest and the largest ser ... [/quote]

[img]http://latex.codecogs.com/gif.latex?\indent\hspace{8bp}$number of choice to do the job$=m\times n[/img]

(2.) 現在，工作變了(how？)少許，我們要先抽出9本書的組合先，再fix其中兩本，再排剩下7本。那麼，式要怎麼變啊？

## 回覆 1# 的帖子

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eaglle 2014-11-22 09:04 AM

## 回覆 2# 的帖子

[size=12pt]In a library, 9 of 10 different books are selected and arranged on a bookshelf. Find the number of arrangement if[/size][size=12pt] [/size]

[size=12pt]1) the books with the smallest and the largest serial numbers "among the 10 books" are to be put on [/size][size=12pt]the left and right ends respectively, in case they are selected.[/size]
[size=12pt][/size]

[[i] 本帖最後由 eaglle 於 2014-11-22 09:08 AM 編輯 [/i]]

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[7] 2014-11-22 12:01 PM

[quote]原帖由 [i]eaglle[/i] 於 2014-11-22 09:04 AM 發表 [url=http://www.discuss.com.hk/redirect.php?goto=findpost&pid=403011212&ptid=24052411][img]http://www.discuss.com.hk/images/common/back.gif[/img][/url]

[[i] 本帖最後由 [7] 於 2014-11-22 12:04 PM 編輯 [/i]]

poiuy1201 2014-11-22 11:00 PM

[url=http://m.discuss.com.hk][img=100,23]http://n2.hk/d/images/r10/mobile.jpg[/img][/url]

[7] 2014-11-22 11:14 PM

[quote]原帖由 [i]poiuy1201[/i] 於 2014-11-22 11:00 PM 發表 [url=http://www.discuss.com.hk/redirect.php?goto=findpost&pid=403061995&ptid=24052411][img]http://www.discuss.com.hk/images/common/back.gif[/img][/url]

http://n2.hk/d/images/r10/mobile.jpg [/quote]第一題，不是8p7x8p7。

[url=http://m.discuss.com.hk][img=100,23]http://n2.hk/d/images/r10/mobile.jpg[/img][/url]

[7] 2014-11-22 11:32 PM

[quote]原帖由 [i]poiuy1201[/i] 於 2014-11-22 11:00 PM 發表 [url=http://www.discuss.com.hk/redirect.php?goto=findpost&pid=403061995&ptid=24052411][img]http://www.discuss.com.hk/images/common/back.gif[/img][/url]

http://n2.hk/d/images/r10/mobile.jpg [/quote]第一題，不是8p7x8p7。

[url=http://m.discuss.com.hk][img=100,23]http://n2.hk/d/images/r10/mobile.jpg[/img][/url]

poiuy1201 2014-11-22 11:38 PM

Ok我再試下，

?

[url=http://m.discuss.com.hk][img=100,23]http://n2.hk/d/images/r10/mobile.jpg[/img][/url]

[7] 2014-11-22 11:39 PM

[quote]原帖由 [i]poiuy1201[/i] 於 2014-11-22 11:00 PM 發表 [url=http://www.discuss.com.hk/redirect.php?goto=findpost&pid=403061995&ptid=24052411][img]http://www.discuss.com.hk/images/common/back.gif[/img][/url]

http://n2.hk/d/images/r10/mobile.jpg [/quote]

[url=http://m.discuss.com.hk][img=100,23]http://n2.hk/d/images/r10/mobile.jpg[/img][/url]

## 回覆 7# 的帖子

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poiuy1201 2014-11-22 11:56 PM

[url=http://m.discuss.com.hk][img=100,23]http://n2.hk/d/images/r10/mobile.jpg[/img][/url]

[7] 2014-11-23 08:04 AM

[quote]原帖由 [i]poiuy1201[/i] 於 2014-11-22 11:38 PM 發表 [url=http://www.discuss.com.hk/redirect.php?goto=findpost&pid=403064994&ptid=24052411][img]http://www.discuss.com.hk/images/common/back.gif[/img][/url]
Ok我再試下，

?

[img]http://n2.hk/d/images/r10/mobile.jpg[/img] [/quote]正確了