问题 解答题

(本小题满分14分)已知10件产品中有3件是次品.

(I)任意取出3件产品作检验,求其中至少有1件是次品的概率;

(II)为了保证使3件次品全部检验出的概率超过0.6,最少应抽取几件产品作检验?

答案

(Ⅰ)17/24…(Ⅱ) 9件

:(1)任意取出3件产品作检验,全部是正品的概率为…………3分

故至少有一件是次品的概率为1-7/24=17/24……………………6分

(2)设抽取n件产品作检验,则3件次品全部检验出的概率为………8分

……………9分

整理得:,……………………11分

  ∴当n=9或n=10时上式成立.…………13分

答:任意取出3件产品作检验,其中至少有1件是次品的概率为17/24,为了保证使3件次品全部检验出的概率超过0.6,最少应抽取9件产品作检验.………………14分

阅读理解

阅读表达。

     People used to say, "The hand that rocks the crade (摇篮) rules the world," and" 2) Behind every successful man, there's a woman." Both these sayings mean the same thing: Men rule the world, but their wives rule them.

     Most of the American women like making their husbands and sons successful. But some of them want

something for themselves. They want good jobs. When they work, they want to be better paid, they want to be

as successful as men.

      The American women's liberation movement 1)_________ __________ by the women who don't want to

stand behind successful men. They don't want to be told that certain jobs of offices are closed to them. They

refuse to work side by side with men who do the same work for a higher pay.

     A liberated woman must be proud of being a woman and confidence herself. If somebody says to her.

"You've come a long way, baby." She'll smile and answer,"Not nearly as far as I'm going to go, baby." This

moment is quite new, and many American women do not agree. But it has already made some important

changes in women's lives-in men's lives, too.

1. 将1)句的空白填入适当的词,使句意完整,上下文通顺:

__________,__________.

2. 将2句译成中文:

________________________________________________________.

3.What must a liberated woman be proud of?

___________________________________________________________________________

4. 在文章中划出与下列句子意思相近的句子:She isn't so satisfied with success.

___________________________________________________________________________

5.根据文章内容,从文中找出或写出一个最适合的标题.

___________________________________________________________________________

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