1 . 等差数列
中,设前
项和为
,
,则
等于( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5733e47b25c81541ddd18dc39c42904a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba48780e63a87aaf7f1d7fa29dd56b5c.png)
A.80 | B.85 | C.90 | D.95 |
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2 . 已知等比数列
中,
,则“
”是 “
”的( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/390636a89883bd64bf8da9bf8654aff9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf172e96f4838656fd2d07256159c96c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d644c849af87fd24c5ac5d46323b8c9.png)
A.充要条件 |
B.充分不必要条件 |
C.必要不充分条件 |
D.既不充分也不必要条件 |
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3 . 已知数列
满足
,
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c3082aa4390cb5575e6030d521e3e37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53271336649378a043f9da8b8bdc1cfc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42e4487468ab2823d6dbf7f0ebd2eb38.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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4 . 投掷一枚质地均匀的骰子两次,记
,
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e263cacd7e20f85b476cd820882032d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a194f60306a39457776584b230520cbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bec76ffd1e94c9023c2241dbd12df8b5.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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5 . 已知等比数列
中,
,且
,那么
的值是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a27d520a002d3eebd1758e2c05c15c3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d27182444d3da4003680f07ec299087c.png)
A.15 | B.31 | C.63 | D.64 |
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6 . 已知离散型随机变量
的分布列为
若
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
X | 0 | 1 |
P |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39d9a8dc1d0be0b09e45bf8eb296a272.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f412feb8dcad5599ddfe1d1ceb00ac0b.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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7 . 若
在
上单调递增,则a的最大值是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dff8704285d8c14ae2bd82f9196501c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c3e441923ed3c1a32720d6aeac2f599.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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8 . 投掷一枚质地均匀的骰子两次,记
两次的点数不同
,
两次的点数之和小于6
,则在
发生条件下
发生的概率为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0d3d1b006b2efda9c789a7a22c9b8b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4ca8bdc812627d925f00ed7c145d696.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b8e8fbba13c61377df60719099971db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4ca8bdc812627d925f00ed7c145d696.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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9 . 从甲地到乙地共有
、
、
三条路线可选择,选路线
堵车的概率为
,选路线
堵车的概率为
,选路线
堵车的概率为
,若李先生从这三条路线中等可能的任选一条开车自驾游,则堵车的概率为( )
![](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/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4646418552dc060ebda1232361a01295.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7412fd1be21e4eaf388963a82ac2b11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29be23f689eb01e57963495377501257.png)
A.0.2 | B.0.3 | C.0.7 | D.0.9 |
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10 . 某校运动会负责播出稿件的志愿者有2人,负责给运动员引领的志愿者有5人,现要从这7人中选出3人组成慰问团,要求每项志愿服务都要有人参与,则不同的选法共有( )
A.16种 | B.20种 | C.25种 | D.28种 |
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