1 . 已知
表示数
,其中数列
单调递增,且
为正整数.当
时,记所有满足条件的
的个数为
当
时,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cec28b5d6e3263275d38599aed15ccd2.png)
______ ;当
时,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b79bd8fd7c11f7ee3f42c409a632b4e.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27effd133986a687e5928c1eb1d27b9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e3a8c295c6019e7b2517a0f6320f4ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ef7ca2b3e8061384501f668e59696a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891c0cae5388125948b70ea4ebc4d9a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31cdbb0647b2b452f47a95dcf736bae2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cec28b5d6e3263275d38599aed15ccd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c8e6b35ef78852d6a39d8eca26847e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b79bd8fd7c11f7ee3f42c409a632b4e.png)
您最近一年使用:0次
2 . 杨辉是南宋末年的一位杰出的数学家、教育家.杨辉三角是杨辉的一项重要研究成果,它的许多性质与组合数的性质有关,杨辉三角中蕴藏了许多优美的规律.如图是一个11阶杨辉三角:________ ;
(2)在第2斜列中,前5个数依次为1,3,6,10,15;第3斜列中,第5个数为35.显然,1+3+6+10+15=35.事实上,一般有这样的结论:第m斜列中(从右上到左下)前k个数之和,一定等于第
斜列中第k个数.试用含有
的数学公式表示上述结论________ .
(2)在第2斜列中,前5个数依次为1,3,6,10,15;第3斜列中,第5个数为35.显然,1+3+6+10+15=35.事实上,一般有这样的结论:第m斜列中(从右上到左下)前k个数之和,一定等于第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0623207595425920f16e76a7f8f268b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8a337585c06eae531379cdfef2745b4.png)
您最近一年使用:0次
3 . 产品抽样检查中经常遇到一类实际问题,假定在N件产品中有M件不合格品,在产品中随机抽
件做检查,发现
件不合格品的概率为
,其中
是
与
中的较小者,
在
不大于合格品数(即
)时取0,否则
取
与合格品数之差,即
.根据以上定义及分布列性质,请计算当N=16,M=8时,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6024f4805db0363088fb74b8c4c8383.png)
_____ ;若
,
,请计算![](https://staticzujuan.xkw.com/quesimg/Upload/formula/665924c7db172f1e1c26bdf998a540df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83b130933397267e76c4d2c720260d6a.png)
_____ .(用组合数表示)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a07ed4354c10be176c28883165b6b3e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5873c01192b7d33b7483f444f90b5b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aec95ea06af2f1bac2b245163a3c6dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5adb213b62fdf991674caace7a218365.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6024f4805db0363088fb74b8c4c8383.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a2dbbaba1b658fe7476197104a2b1a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd40c3e2e1a5bf8493af1047fa8602ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/665924c7db172f1e1c26bdf998a540df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83b130933397267e76c4d2c720260d6a.png)
您最近一年使用:0次
名校
解题方法
4 . 二进制数是用0和1表示的数,它的基数为2,进位规则是“逢二进一”,借位规则是“借一当二”,二进制数
对应的十进制数记为
,即
,其中
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1065440ee09654f97b50b5ef6a963ad.png)
,则在
,
,
,…,
中恰好有2个0的所有二进制数
对应的十进制数的总和为__________ (用数字作答)
将五个数20、23、2、0、3任意次序排成一行,拼成一个7位数,则能产生不同的7位数的个数是__________ (用数字作答)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9e0d6a5c78bc75b0acae1734e097a61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9369d6e6f9022be0f24b7e0c7f86d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8687b285b4e35d171dfc68e5a5aa18e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/489340c9a2d70c00bae13b7018cad448.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1065440ee09654f97b50b5ef6a963ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d2b832dbcf0b9e118324d9301d905b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f35f7dcce39f3d4dc6b7faf84dc1d0a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3b44005ff870c21140b3c2f2e7555f7.png)
将五个数20、23、2、0、3任意次序排成一行,拼成一个7位数,则能产生不同的7位数的个数是
您最近一年使用:0次
5 . (1)计算![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a54a63e17d98d186c5e61f320ef0dfce.png)
________ (请用数字作答).
(2)已知
,则实数x的值为____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a54a63e17d98d186c5e61f320ef0dfce.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae7a0d736c92a8a65d7d3e7f06dcb846.png)
您最近一年使用:0次
6 . 在杨辉三角中,每一个数值是它上面两个数值之和,这个三角形开头几行如图,则第9行从左到右的第1行第3个数是______ ;若第
行从左到右第12个数与第13个数的比值为
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f3cb8d72bb2e281b943b3b430138ef7.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b2a698891d42c70b597f0da4f215f09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f3cb8d72bb2e281b943b3b430138ef7.png)
![](https://img.xkw.com/dksih/QBM/2020/5/14/2462789262827520/2464042859126784/STEM/d0cce146d22a4a8581d12ceeead3a4bb.png?resizew=266)
您最近一年使用:0次