不用写出过程,只要写一下每一题的答案和大概怎么做的就行了,感激不尽10.Aboxcontains6whitemarbles,7redmarbles,and8bluemarbles.(a)Ifyouchoose3marblesatrandomfromthebox,whatistheprobabilitythattheyare|小学英语问答-字典翻译问答网

问题标题：

不用写出过程,只要写一下每一题的答案和大概怎么做的就行了,感激不尽10.Aboxcontains6whitemarbles,7redmarbles,and8bluemarbles.(a)Ifyouchoose3marblesatrandomfromthebox,whatistheprobabilitythattheyare

问题描述：

不用写出过程,只要写一下每一题的答案和大概怎么做的就行了,感激不尽

10.Aboxcontains6whitemarbles,7redmarbles,and8bluemarbles.

(a)Ifyouchoose3marblesatrandomfromthebox,whatistheprobabilitythattheyare

allthesamecolor?

(b)Supposeinsteadyouchoosethe3marblesoneatatime,andeachtimeyouchoose

amarble,youreturnittotheboxbeforedrawingthenextmarble.Whatisthe

probabilitythatallthreemarblesarethesamecolor?

11.Ifyouaredealt5cardsfromastandard52-carddeck,whatistheprobabilitythatyouwill

getatleastonecardofeachsuit?

12.Suppose10couplesattendanevent,andall20peopleenteraraffle.Fourofthe20people

areselectedatrandomtowin$10intheraffle.Whatistheprobabilitythatatleastone

coupletakeshome$20,whichwilloccurifboththehusbandandwifewintheraffle?

13.Supposethat10peopleattendagathering.

(a)Supposethe10peopleconsistof5couples(eachconsistingofahusbandandawife).

Ifthemenandwomenarepairedupatrandom,witheachpairconsistingofaman

andawoman,whatistheprobabilitythateveryonegetspairedwithhisorherspouse?

(b)Supposethe10peopleconsistof5setsoftwinsisters.Ifthe10peoplearethen

groupedinto5pairsatrandom,whatistheprobabilitythateveryonegetspairedwith

hertwin?

刘逸敏回答：

　　10（a）(c(3,6)+c(3,7)+c(3,8))/c(3/21); 　　(b)(6/21)*(6/21)*(6/21)+(7/21)*(7/21)*(7/21)+(8/21)*(8/21)*(8/21); 　　11.c(1,13)*c(1,13)*c(1,13)*c(1,13)*c(1,48)/c(5,52); 　　12.c(1,10)*c(2,2)*c(2,18)/c(4,20); 　　13.(a)A(5,5)*A(5,5)*A(2,2)/A(10,10); 　　(b)A(5,5)*A(2,2)/A(10,10);

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