Question

数字 $1$ 到 $49$ 从中心开始按螺旋形排列在一个正方形网格上。下方网格中已经填入了前几个数字。考虑与数字 $7$ 在同一条对角线上的四个阴影方格中将出现的数字。这四个数字中有多少个是质数？

The numbers from $1$ to $49$ are arranged in a spiral pattern on a square grid, beginning at the center. The first few numbers have been entered into the grid below. Consider the four numbers that will appear in the shaded squares, on the same diagonal as the number $7.$ How many of these four numbers are prime?

$0$

$1$

$2$

$3$

$4$

答案：D

知识点：质数找规律

难度评级：960

视频讲解：

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文字解答：

完成螺旋后得到下图。

阴影方格中的质数是 $19, 23$ 和 $47$ ，共有三个。

所以正确答案是 D。

We can fill in the other numbers to get the complete grid.

From this, we can see that the only prime numbers in the shaded boxes are $19, 23,$ and $47.$

Thus, D is the correct answer.

2023 AMC 8 第 4 题

答案：D

难度评级：960

视频讲解：

文字解答：

其他年份的第 4 题