Question

一枚公平硬币被抛三次。至少出现两个连续正面的概率是多少？

A fair coin is tossed 3 times. What is the probability of at least two consecutive heads?

$\dfrac{1}{8}$

$\dfrac{1}{4}$

$\dfrac{3}{8}$

$\dfrac{1}{2}$

$\dfrac{3}{4}$

答案：C

知识点：基本概率系统列举

难度评级：960

视频讲解：

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文字解答：

至少有两个连续正面的结果是 $HHT$ 、 $THH$ 和 $HHH$ 。三次公平抛硬币共有 $2^3=8$ 个等可能结果，所以概率为 $\dfrac{3}{8}$ 。

所以正确答案是 C。

The outcomes with at least two consecutive heads are $HHT$ , $THH$ , and $HHH$ . There are $2^3=8$ equally likely outcomes from three fair coin tosses, so the probability is $\dfrac{3}{8}$ .

Thus, C is the correct answer.

2013 AMC 8 第 8 题

答案：C

难度评级：960

视频讲解：

文字解答：

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