Question

在 Xochi 教授班最近的一次考试中：

• $5$ 名学生得分至少为 $95\%$ ，

• $13$ 名学生得分至少为 $90\%$ ，

• $27$ 名学生得分至少为 $85\%$ ，

• $50$ 名学生得分至少为 $80\%$ 。

有多少名学生得分至少为 $80\%$ 且低于 $90\%$ ？

On the most recent exam in Prof. Xochi's class,

• $5$ students earned a score of at least $95\%,$

• $13$ students earned a score of at least $90\%,$

• $27$ students earned a score of at least $85\%,$ and

• $50$ students earned a score of at least $80\%.$

How many students earned a score of at least $80\%$ and less than $90\%?$

$8$

$14$

$22$

$37$

$45$

答案：D

知识点：数据与图表解读

难度评级：770

视频讲解：

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文字解答：

注意各档人数逐步增加，这是因为条件变得越来越宽。

要包括所有至少 $80\%$ 的 $50$ 名学生，但排除所有至少 $90\%$ 的 $13$ 名学生。因此答案是 $50 - 13 = 37$ ，选 D。

Notice that the numbers of students in each category keep increasing, which makes sense because the categories are getting broader.

We want to include all $50$ of the students who earned a score of at least $80\%$ but exclude all $13$ of the students who earned a score of at least $90\%.$ So, the answer is $50 - 13 = 37,$ which is choice D.

2025 AMC 8 第 7 题

答案：D

难度评级：770

视频讲解：

文字解答：

其他年份的第 7 题