题目内容

【题目】用这六个数字.

(1)能组成多少个无重复数字的四位偶数?

(2)能组成多少个无重复数字且为的倍数的五位数?

(3)能组成多少个无重复数字且比大的四位数?

【答案】(1)(2)(3)

【解析】(1)符合要求的四位可分为三类:第一类:在个位时有个;

第二类:在个位时,首位从中选定个(有种),十位和百位从余下的数字中选(有种),于是有个;

第三类:在个位时,与第二类同理,也有个,由分类加法计算原理知,共有四位偶数个.

(2)符合要求的五位数可分为两类:个位数上的数字是的五位数有个,个位数上的数字是的五位数有个,故满足条件的五位数的个数共有个.

(3)比大的四位偶数可分为三类:

第一类:形如共有个;

第二类:形如, 共有个;

第三类:形如,共有个.

由分类加法计数原理知,无重复数字且比大的四位数共有个.

练习册系列答案
相关题目

【题目】阅读下面的文言文,完成问题。

颜斶①说齐王

齐宣王见颜斶,曰:“斶前!”斶亦曰:“王前!”宣王不说。左右曰:“王,人君也;斶,人臣也;王曰‘斶前’,亦曰‘王前’,可乎?”斶对曰:“夫斶前为慕势,王前为趋士;与使斶为趋势,不如使王为趋士。”王忿然作色曰:“王者贵乎,士贵乎?”对曰:“士贵耳,王者不贵。”王曰:“有说乎?”斶曰:“有。昔者秦攻齐,令曰:‘有敢去柳下季②垄③五十步而樵采者,死不赦。’令曰:‘有能得齐王头者,封万户侯,赐金千镒。’由是观之,生王之头曾不若死士之垄也。”宣王默然不说。

宣王曰:“嗟乎,君子焉可侮哉!寡人自取病耳。愿请受为弟子。且颜先生与寡人游,食必太牢,出必乘车,妻子衣服丽都。”颜斶辞去,曰:“夫玉生于山,制则破焉;非弗宝贵矣,然夫璞不完。士生乎鄙野,推选则禄焉;非不得尊遂也,然而形神不全。斶愿得归,晚食以当肉,安步以当车,无罪以当贵,清静贞正以自虞。”则再拜而辞去。

君子曰:斶知足矣,归真反璞,则终身不辱。

【注】①颜斶:齐国隐士。②柳下季:即柳下惠,姓展名禽字季,鲁国贤人,居于柳下。③垄:指坟墓。

【1】对下列句子中画线字的解释,不正确的一项是

A.宣王不说 说:通“悦”,高兴

B.夫斶前为慕势 前:名词用作动词,上前

C.士生乎鄙野 鄙:以……为边邑

D.则再拜而辞去 去:离去,离开

【2】下列句子中,加粗字的意义和用法相同的一组是

A. B.

C. D.

【3】以下句子分别编为四组,全都表明颜斶不慕权势、保持士的高尚气节的一组是

①斶亦曰:“王前!”

②左右曰:“王,人君也;斶,人臣也;王曰‘斶前’,亦曰‘王前’,可乎?”

③斶对曰:“……与使斶为趋势,不如使王为趋士。”

④王忿然作色曰:“王者贵乎,士贵乎?”

⑤颜斶辞去,曰:“……士生乎鄙野,推选则禄焉;非不得尊遂也,然而形神不全。……”

A.①③④

B.①③⑤

C.③④⑤

D.②④⑤

【4】下列对原文有关内容的理解和分析不正确的一项是

A.齐宣王召见颜斶时让颜斶上前来,颜斶也让大王上前来,惹得齐宣王很不高兴。

B.颜斶谈到砍下齐王头颅封邑万户、赐金千镒的事情,意在说明“王者”尊贵。

C.齐宣王最终认识到随便侮辱士人是自讨没趣的做法,于是就请求做颜斶的学生。

D.颜斶没有接受齐宣王做学生的请求,郑重地辞王而去,回到本乡,终身不受侮辱。

【5】将下列句子翻译成现代汉语。

①王忿然作色曰:“王者贵乎,士贵乎?”

②由是观之,生王之头曾不若死士之垄也。

③晚食以当肉,安步以当车。

【题目】根据短文内容.完成下列句子.每空一词。

When we got to the hospital, we found Dad still coughed a lot, but his smile was as sure as ever. It was another attack of pneumonia(肺炎). My husband and I stayed with him for the weekend, but we had to go back to our jobs on Monday. Local relatives would help Dad get home from the hospital and look after him. But I wanted to let him know that we also cared about him. even when we weren't with him.

Then I remembered a family tradition when our children were small. Before leaving their grandparents' home after a visit, each child would write a love note to their grandparents. For days, their grandparents would smile as they read these notes of love.

So when I cleaned Dad's kitchen and made the bed for him, I wrote some notes. Some were like this, "Dad, I put the food in the fridge. " Some expressed my love, "Dad, I hope you will sleep well in your new bed. " Most notes were put downstairs where he would stay for several weeks when he was ill. But I put one note upstairs under his pillow(枕头), "Dad, if yon have found this note, you must be feeling better. We are so glad!"

"These notes helped improve his health. Several weeks later, in one of our regular phone calls, I asked Dad how he was doing. He said, "Pretty good. I just found your note under my pillow upstairs!

【1】 The writer's father was and was sent to ____________.

【2】The writer to her job after she stayed with her father for the __________.

【3】It was a family for the children to write love to their grandparents.

【4】The writer did the thing as her children to about her father.

【5】A few weeks later, when the writer heard her father's , she knew he felt much _________.

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网