先后投硬币3次,则至少2面正面朝上的概率是?
先后投硬币3次,则至少2面正面朝上的概率是?
不是1/2吗?
不是1/2吗?
数学人气:688 ℃时间:2020-03-21 19:46:30
优质解答
很简单,它的概率可以看成1-(一面正面朝上的概率)-(全部反面朝上的概率),也就是1-3/8-1/8=1/2.就是1/2.
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