1 . 将三张相同卡片的正面分别写“2”,“4”,“6”.将背面朝上洗匀后随机抽出一张卡片,将该卡片上的数作为十位数,再从余下的两张卡片中随机抽出一张卡片,将该卡片上的数作为个位数,所得的两位数能被4整除的概率是( )
A.![]() | B.![]() | C.![]() | D.![]() |
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2 . 给出下列四个命题:
(1)当
时,
;
(2)当
且
时,
;
(3)设
是方程
的两个根,则
;
(4)设
,若关于
的方程
的解集为
,则
且
.
其中真命题的个数是( )
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52e64e96b958788b40b4b286a2c4edc8.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c400a615a16a1662de98dfb4e49d58d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ec9be2faf8e743df2fb0bbf56554e73.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4e288596fa3811dd2c17bded60e82e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41fe511fd1cbb045a82c8f1087e7b7f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b757f4353577c9a4f68153e0b2f9d107.png)
(4)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73254f32b6da29ecc32df2e9f87a4c97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40cb7125a7b832153bb37fb614a73e6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf3ed15aa3dcc4211fb520b5b942c989.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b4d795709b0abcf47bceec2250f2f9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/143b917df0520097be222accbddf9394.png)
其中真命题的个数是( )
A.1个 | B.2个 | C.3个 | D.4个 |
您最近一年使用:0次