2019 AMC 12B 第 1 题

Question

Alicia 有两个容器。第一个装了

\dfrac{5}{6}

容积的水，第二个是空的。她把第一个容器中的水全部倒入第二个容器，此时第二个容器装了

\dfrac{3}{4}

容积的水。第一个容器的体积与第二个容器的体积之比是多少？

Alicia had two containers. The first was

\dfrac{5}{6}

full of water and the second was empty. She poured all the water from the first container into the second container, at which point the second container was

\dfrac{3}{4}

full of water. What is the ratio of the volume of the first container to the volume of the second container?

\dfrac{5}{8}

\dfrac{4}{5}

\dfrac{7}{8}

\dfrac{9}{10}

\dfrac{11}{12}

答案：D

知识点：比与比例分数

难度评级：880

小提示：

倒水前后水的体积不变

The amount of water is unchanged when it is poured

大提示：

\dfrac{5}{6}V_1=\dfrac{3}{4}V_2

。

\dfrac{5}{6}V_1=\dfrac{3}{4}V_2

解答：

倒水前后水的体积相同，所以

\dfrac{5}{6}V_1=\dfrac{3}{4}V_2

。

因此

\dfrac{V_1}{V_2}=\dfrac{\frac{3}{4}}{\frac{5}{6}}=\dfrac{3}{4}\cdot\dfrac{6}{5}=\dfrac{9}{10}\text{。}

所以正确答案是 D。

The volume of water is the same before and after, so

\dfrac{5}{6}V_1=\dfrac{3}{4}V_2.

Then

\dfrac{V_1}{V_2}=\dfrac{\frac{3}{4}}{\frac{5}{6}}=\dfrac{3}{4}\cdot\dfrac{6}{5}=\dfrac{9}{10}.

Thus, D is the correct answer.

2019 AMC 12B 第 1 题

答案：D

难度评级：880

小提示：

大提示：

解答：

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