1 . 甲乙两人参加竞选,结果是甲得
票,乙得
票
. 试求:唱票中甲累计的票数始终超过乙累计的票数的概率.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/711ba99b95ca9b682e865865a404e980.png)
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2 . 将
、
、
、
、
、
排成一排,其中
、
都不与
相邻的不同排法种数为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
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3 . 若从集合
中,取出三元子集
,使得同时满足:
,
,则所有这样的子集
的个数是__________ .(用具体的数字做答).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d978d72876edbbdc94bd43a0f87b6652.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d020cd453031ae9eede7961ec78f21a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5eb2b089db06ba3a2459e03f943b3477.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4a3c386db065ccd66239a505e351576.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
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4 . 设
是
的任意排列,部分和数列
,
,……
,若数列
中的每一项都不能被3整除,则这样的排列有种______ 种.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29f983d04b2126cf521c016963b091c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/343a27ed5f83531142a9b189eeacfee1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87b5be17a0c57838a0584bb501372fbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6907ef1e6649faf4cde69070a5b77ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9b8d99028897e78863ddcbee57adf64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50ee9e04f46de4629bb7b1dbbbb33465.png)
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5 . 圆周上有10个等分点.则以这10个等分点中的4个点为顶点的凸四边形中,梯形所占的个数比为______ .
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6 . 设
,
.对于
的一个排列
,如果存在
,使得
成立,则称该排列具有性质
,设具有性质
的排列数为
,不具有性质
的排列数为
,证明:
在区间
内.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28652e52c0b02a343e618935ea625cbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5818ede14d21f6df9ef9c2bfe09286c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eb1d5bdd1d41e00b60386965f039735.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51442d737543af8eec871b4dfb625934.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a4fe97453436bf73e4d1ed860508935.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93bfa433665b525bce7702362d1acc45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77ab1256702aef4e9f1a5eb6c12ecc96.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fbd67f60f04c278bdd867fdb3979dfb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/853a7bac30a8ece56f82ad319f3f14b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5265d99095b635f62c7915298ec0e963.png)
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7 . 四个家庭依次记为甲、乙、丙、丁,每家四人,大家分四组进行四人比赛.那么,至少有两组、每组四人来自不同家庭的概率为______ .
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8 . 如图,正六边形
的中心为
,对
、
、
、
、
、
、
这七个点中的任意两点,以其中一点为起点、另一点为终点作向量.任取其中两个向量,以它们的数量积的绝对值作为随机变量
.试求
的概率分布列及其数学期望
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33470bee4febd946d39f7b63d6344c8f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/7/e96fb917-64f4-4024-bf48-2f1be4e4f6da.png?resizew=141)
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9 . 任意相邻两位数码之和均能被3整除的五位数的个数是______ .
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10 . 在一个以长方体的四个顶点为顶点的四面体中,四个面都是直角三角形的四面体有个.
A.8 | B.16 | C.24 | D.48 |
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