-
1一盒子内有10只球,其中6只是白球,4只是红球,从中取2只球,则取出产品中至少有一个是白球的概率为( )。
A.![1555150136244967.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136244967.png)
B.![1555150136633852.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136633852.png)
C.![1555150136488320.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136488320.png)
D.![1555150136390477.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136390477.png)
开始考试点击查看答案 -
2一盒子内有10只球,其中4只是白球,6只是红球,从中取三只球,则取的球都是白球的概率为( )。
A.![1555150136814869.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136814869.png)
B.![1555150136830832.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136830832.png)
C.![1555150136412769.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136412769.png)
D.![1555150136316724.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136316724.png)
开始考试点击查看答案 -
3从5个男生和4个女生中选出3个代表,求选出全是女生的概率( )。
A.![1555150136508786.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136508786.png)
B.![1555150136139175.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136139175.png)
C.![1555150136229095.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136229095.png)
D.![1555150136768230.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136768230.png)
开始考试点击查看答案 -
4任选一个不大于40正整数,则选出的数正好可以被7整除的概率为( )。
A.![1555150136584629.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136584629.png)
B.![1555150136260429.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136260429.png)
C.![1555150136400836.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136400836.png)
D.![1555150136319106.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136319106.png)
开始考试点击查看答案 -
5二元函数
![1555150136508314.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136508314.png)
的( )。
A.极小值为![1555150136417150.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136417150.png)
B.极大值为![1555150136376152.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136376152.png)
C.极小值为![1555150136513285.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136513285.png)
D.极大值为![1555150136137394.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150136137394.png)
开始考试点击查看答案 -
A.![1555150137654046.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137654046.png)
B.![1555150137345839.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137345839.png)
C.![1555150137220929.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137220929.png)
D.![1555150137320470.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137320470.png)
开始考试点击查看答案 -
7甲、乙二人同时向一目标射击,甲、乙二人击中目标的概率分别为0.7和0.8,则甲、乙二人都击中目标的概率为( )。
A.0.75
B.0.56
C.0.5
D.0.1
开始考试点击查看答案 -
8设随机变量X的分布列为
![1555150137513776.jpg](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137513776.jpg)
则
![1555150137437408.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137437408.png)
( )。
A.0.1
B.0.2
C.0.3
D.0.4
开始考试点击查看答案 -
9设随机变量X的分布列为
![1555150137496988.jpg](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137496988.jpg)
则
![1555150137669438.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137669438.png)
( )。
A.0.4
B.0.5
C.0.6
D.0.7
开始考试点击查看答案 -
10设离散型随机变量ξ的分布列为
![1555150137192988.jpg](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137192988.jpg)
则ξ的数学期望( )。
A.![1555150137604785.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137604785.png)
B.![1555150137416540.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137416540.png)
C.![1555150137655517.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137655517.png)
D.![1555150137744454.png](https://www.changlipeixun.com/d/tiku/ueditor/image/20190413/1555150137744454.png)
开始考试点击查看答案