题库网 (tiku.one)

 找回密码
 立即注册

 

      

上传图片附件

未使用图片

小贴士: 允许的图片文件格式为: gif, jpg, jpeg, png, webp,上传完成后会在上方生成预览,用鼠标连续双击缩略图,或拖动缩略图,该图片就被绑定至本题,显示在题目下方

本次作答已使用

小贴士: 此栏目显示的是当前作答使用的所有图片,绑定到某一题目的图片同时会显示在该题目下方; 删除使用的图片会将其转移到<未使用图片>类别


习题练习:Counting Principles 



 作者: admin发布日期: 2024-06-02 22:24   总分: 16分  得分: _____________

答题人: 匿名未登录  开始时间: 24年06月02日 22:24  切换到: 整卷模式

标记此题
1#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Find the number of ways in which twelve different baseball crzi ir :2s2k-oards can be given to Emily, Harry, John and Olivia, if Emily is to receive 5 cards, Harry is to receive 3 cards, John is to receive 3 cards and Olivia is to receive2os i2:zrkr -i 1 card.   

参考答案:     查看本题详细解析

标记此题
2#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Tyler needs to decide the order in which to schedu2* l3rbllr h,jle 11 exams for his school. Two of these exams are Chemistry ( 1 SL and 1 HL). Find the number of different ways 2b *hjl r,llr3Tyler can schedule the 11 exams given that the two Chemistry subjects must not be consecutive.$\approx a \times 10^{b}$ a =    b =   

参考答案:     查看本题详细解析

标记此题
3#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A school basketball team of 5 students is selected frpzk(sh k158jt( ll8sifx -tvcx ;/wm(om 8 boys and 4 girls.
1. Determine how many possible teams can be chosen.   
2. Determine how many teams can be formed consisting of 3 boys and 2 girls?   
3. Determine how many teams can be formed consisting of at most 3 girls?   

参考答案:     查看本题详细解析

标记此题
4#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A police department has 4 may: z80i 7g gdprpl;+e,c tvb0ale and 7 female officers. A special group of 5 officers is to be assz0ldy p p,:7rgc +t08ga b;eviembled for an undercover operation.
1. Determine how many possible groups can be chosen.   
2. Determine how many groups can be formed consisting of 2 males and 3 females.   
3. Determine how many groups can be formed consisting of at least one male.   

参考答案:     查看本题详细解析

标记此题
5#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In an art museum, there are 8 different p.aixnidpq( +gb)/zt 9 euv- h*aintings by Picasso, 5 different paintings by Van Gogh, atv9eqz)d.ax+- niiu(hp g/* bnd 3 different paintings by Rembrandt. The curator of the museum wants to hold an exhibition in a hall that can only display a maximum of 7 paintings at a time.
The curator wants to include at least two paintings from each artist in the exhibition.
1. Given that 7 paintings will be displayed, determine how many ways they can be selected.   
2. Find the probability that more Rembrandt paintings will be selected than Picasso paintings or Van Gogh paintings.   

参考答案:     查看本题详细解析

标记此题
6#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Peter needs to decide the order in which to schedule 14 exams for his s d9 xspi0-8oxcchool. Two of these exams are Chemistry ( 1 SL and 1 HL). Find the number of different ways Peter c pdcxxo0 i-9s8an schedule the 14 exams given that the two Chemistry subjects must not be consecutive.$\approx a \times 10^{b}$ a =    b =   

参考答案:     查看本题详细解析

标记此题
7#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Ten students are to be arranged in a lrry1i( ;cjn 0new chemistry lab. The chemistry lab is set out riy1lcr(;0nj in two rows of five desks as shown in the following diagram.



1. Find the number of ways the ten students may be arranged in the lab.

Two of the students, Hugo and Leo, were noticed to talk to each other during previous lab sessions.   
2. Find the number of ways the students may be arranged if Hugo and Leo must sit so that one is directly behind the other. For example, Dest 1 and Desk 6 .   
3. Find the number of ways the students may be arranged if Hugo and Leo must not sit next to each other in the same row.   

参考答案:     查看本题详细解析

标记此题
8#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
An arts and crafts store is offering a special package on pe70t fii -4s-ylas8 q qzg1f5xkrsonalized keychains. Customers can choose to personalize their keychains with up to 3 differe l 7kgxqz5tisf4a y0-iqs8f1-nt charms from a selection of 6 different types of charms.
Determine how many ways a customer can personalize a keychain if
1. The order is important.
2. The order is not important.
参考答案:     查看本题详细解析

标记此题
9#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A professor and five of his students attend a talk given in a lecture series./ 9suv1umbbp7c),gv v They have a row of 8 seats to themselves c) vvmbb uus1g7p/,9v.
Find the number of ways the professor and his students can sit if
1. the professor and his students sit together.   
2. the students decide to sit at least one seat apart from their professor.   

参考答案:     查看本题详细解析

标记此题
10#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Julie works at a book store and has nine6 w-8lx g6ff+potb 3pd books to display on the main shelf of the store. Four of the books are non-fiction and five are fiction. Each book is different. Determine the number of possible ways Julie can line up the nine books on the main shelf, -pw63fxf+l tp b8g6odgiven that
1. the non-fiction books should stand together;   
2. the non-fiction books should stand together on either end;   
3. the non-fiction books should stand together and do not stand on either end.   

参考答案:     查看本题详细解析

标记此题
11#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Sophia and Zoe compete in a freestyle swimming race wmxl l+6)4kys lhere there are no tied finishes and there is a total of 10 competitormll6l s )kx4y+s. Find the total number of possible ways in which the ten swimmers can finish if Zoe finishes
1. in the position immediately after Sophia;   
2. in any position after Sophia.   

参考答案:     查看本题详细解析

标记此题
12#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  There are 11 players on a football team who are asked to line up in one hloa/0z3 3ra;1 uh cz+epoy qj84mnx0 straight line for a team photo. Three of the team members named Adam, Brad and Chris refuse to stand next to each other.m/;y r3 jcqn1zzp+e o hl40h8 uxo03aa There is no restriction on the order in which the other team members position themselves.
Find the number of different orders in which the 11 team members can be positioned for the photo.   

参考答案:     查看本题详细解析

标记此题
13#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  There are six office cubicles arranged in a grid with two +fn4x qknh:caxh3b* . rows and three columns as shb. kfxnq +nahc 4*xh3:own in the following diagram. Aria, Bella, Charlotte, Danna, and Emma are to be stationed inside the cubicles to work on various company projects.
Find the number of ways of placing the team members in the cubicles in each of the following cases.
1. Each cubicle is large enough to contain the five team members, but Danna and Emma must not be placed in the same cubicle.   
2. Each cubicle may only contain one team member. But Aria and Bella must not be placed in cubicles which share a boundary, as they tend to get distracted by each other.   

参考答案:     查看本题详细解析

标记此题
14#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The barcode strings of a new productvg qof;p-2d +6lplnrz((ej 8q are created from four letters $ \mathrm{A}$, $\mathrm{B}$, $\mathrm{C}$, $\mathrm{D}$ and ten digits $0,1,2, \ldots, 9$ . No three of the letters may be written consecutively in a barcode string. There is no restriction on the order in which the numbers can be written. Find the number of different barcode strings that can be created.$\approx a \times 10^{b}$ a =    b =   

参考答案:     查看本题详细解析

标记此题
15#
 
填空题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Sophie and Ella play a game. They each have f eqpmr rhzb umc-76rs2 n:7a,z(ig1+kive cards showing roman numerals I, V, X, L, C. Sophie lays her cards face mump2q,a6ce 7gzk r+ bh-ri :1(szn7 rup on the table in order I, V, X, L, C as shown in the following diagram.


Ella shuffles her cards and lays them face down on the table. She then turns them over one by one to see if her card matches with Sophie's 4 card directly above. Sophie wins if no matches occur; otherwise Ella wins.
1. Show that the probability that Sophie wins the game is $\frac{11}{30}$ .

Sophie and Ella repeat their game so that they play a total of 90 times. Let the discrete random variable X represent the number of times Sophie wins.   
2. Determine:
1. the mean of X ;   
2. the variance of X .   

参考答案:     查看本题详细解析

标记此题
16#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
Jack and John have decided t .mjvnx;uw74a o play a game. They will be rolling a die seven times. One roll of a die is considered as one round of the game. On each round, John agrees to pay Jack 4 dollars if 1 or 2 is rolled, Jack agrex7 4;au mjnvw.es to pay John 2 dollars if 3,4,5 or 6 is rolled, and who is paid wins the round. In the end, who earns money wins the game.
1. Show that the probability that Jack wins exactly two rounds is $\frac{224}{729}$ .
2. 1. Explain why the total number of outcomes for the results of the seven rounds is 128 .
2. Expand $(1+y)^{7}$ and choose a suitable value of y to prove that

$128=\binom{7}{0}+\binom{7}{1}+\binom{7}{2}+\binom{7}{3}+\binom{7}{4}+\binom{7}{5}+\binom{7}{6}+\binom{7}{7}$ .

3. Give a meaning of the equality above in the context of the seven rounds.
3. 1. Find the expected amount of money earned by each player in the game.
2. Who is expected to win the game?
3. Is this game fair? Justify your answer.
4. Jack and John have decided to play the game again.
1. Find an expression for the probability that John wins five rounds on the first game and two rounds on the second game. Give your answer in the form

$\binom{7}{r}^{2}\left[\frac{1}{3}\right]^{s}\left[\frac{2}{3}\right]^{t}$

where the values of r, s and t are to be found.
2. Use your answer to (d) (i) and seven similar expressions to write down the probability that John wins a total of seven rounds over two games as the sum of eight probabilities.
3. Hence prove that

$\binom{14}{7}=\sum_{k=0}^{7}\binom{7}{k}^{2}$

5. Now Jack and John roll a die 12 times. Let A denote the number of rounds Jack wins. The expected value of A can be written as

$\mathrm{E}[A]=\sum_{r=0}^{12} r\binom{12}{r}\left[\frac{a^{12-r}}{b^{12}}\right]$

1. Find the value of a and b .
2. Differentiate the expansion of $(1+y)^{12}$ to prove that the expected number of rolls Jack wins is 4 .

本题所包含的其它图片:

参考答案:     查看本题详细解析

  • :
  • 总分:16分 及格:9.6分 时间:不限时
    未答题: 已答题:0 答错题:
    当前第 题,此次习题练习共有 16 道题
    本系统支持习题练习,作业与考试三大模式,作业考试自动评分,成绩排序一键导出,可设定动态变量同一试卷千人千题
    如果您对本系统感兴趣,想加入我们或者想进行任何形式的合作,请加微信 skysky1258

    浏览记录|使用帮助|手机版|切到手机版|题库网 (https://tiku.one)

    GMT+8, 2024-11-22 04:52 , Processed in 0.088572 second(s), 53 queries , Redis On.