问题 解答题

在一个不透明的盒子中放有四张分别写有数字1、2、3、4的红色卡片和三张分别写有数字1、2、3的蓝色卡片,卡片除颜色和数字外其他完全相同。

(1)从中任意抽取一张卡片,求该卡片上写有数字1的概率;

(2)将3张蓝色卡片取出后放入另外一个不透明的盒子内,然后在两个盒子内各任意抽取一张卡片,以红色卡片上的数字作为十位数,蓝色卡片上的数字作为个位数组成一个两位数,求这个两位数大于22的概率。

答案

解:(1)列树形图如下,

出现“1”的结果有2种,

∴P(出现1)=

(2)所组成2位数大于22结果有7种,

∴P(2位数>22)=

阅读理解

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小题1:Bamboo is a kind of grass because _______.

A.it grows quickly

B.it isn’t as high as a tree

C.it doesn’t grow in forests

D.it is hollow小题2:What kind of bamboo flooring is best?

A.The strongest kind.

B.The most expensive kind.

C.The kind that has a beautiful color.

D.The kind that contains no formaldehydes.小题3:How can bamboo make a contribution to the environment?

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A.explain the importance of bamboo flooring

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D.discuss the history of hardwood flooring

判断题