Question

Abe 手里有 $1$ 颗绿色和 $1$ 颗红色软糖。Bea 手里有 $1$ 颗绿色、 $1$ 颗黄色和 $2$ 颗红色软糖。两人各随机拿出一颗软糖给对方看。颜色相同的概率是多少？

Abe holds $1$ green and $1$ red jelly bean in his hand. Bea holds $1$ green, $1$ yellow, and $2$ red jelly beans in her hand. Each randomly picks a jelly bean to show the other. What is the probability that the colors match?

$\dfrac{1}{4}$

$\dfrac{1}{3}$

$\dfrac{3}{8}$

$\frac{1}{2}$

$\dfrac{2}{3}$

答案：C

知识点：基本概率分类讨论

难度评级：1140

视频讲解：

Click to load, then click again to play

文字解答：

Abe 和 Bea 选择软糖共有 $2\cdot4=8$ 种等可能结果。颜色相同可能是两人都选绿色，有 $1$ 种；也可能两人都选红色，有 $1\cdot2=2$ 种。

因此 $8$ 个结果中有 $3$ 个颜色相同，概率为 $\dfrac{3}{8}$ 。

所以正确答案是 C。

There are $2\cdot4=8$ equally likely ways for Abe and Bea to choose their jelly beans. The colors match if they both choose green, which can happen in $1$ way, or if they both choose red, which can happen in $1\cdot2=2$ ways.

Thus $3$ of the $8$ outcomes match, for probability $\dfrac{3}{8}$ .

Thus, C is the correct answer.

2013 AMC 8 第 14 题

答案：C

难度评级：1140

视频讲解：

文字解答：

其他年份的第 14 题