问题 填空题

袋子中装有3个白球、3个绿球和6个红球,这些球除颜色外都相同,从袋中任意摸出1个球,则P(摸到白球)=______,则P(摸到白球或红球)=______.

答案

∵有3个白球、3个绿球和6个红球,

∴袋子中共有12个球,

∴从袋中任意摸出1个球,P(摸到白球)=

3
12
=
1
4

P(摸到白球或红球)=

3+6
12
=
3
4

故答案为:

1
4
3
4

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(2)这篇文章发表后有什么作用?

                                                                                                                                                             

                                                                                                                                                             

(3)在随后召开的十一届三中全会中,确立了什么思想路线?

                                                                                                                                                            

问答题