Question

Kymbrea 的漫画书收藏目前有 $30$ 本漫画书，并且她每月增加 $2$ 本。LaShawn 的收藏目前有 $10$ 本漫画书，并且他每月增加 $6$ 本。多少个月后，LaShawn 收藏的漫画书数量会是 Kymbrea 的两倍？

Kymbrea's comic book collection currently has $30$ comic books in it, and she is adding to her collection at the rate of $2$ comic books per month. LaShawn's collection currently has $10$ comic books in it, and he is adding to his collection at the rate of $6$ comic books per month. After how many months will LaShawn's collection have twice as many comic books as Kymbrea's?

$1$

$4$

$5$

$20$

$25$

答案：E

知识点：一次方程

难度评级：920

解答：

$m$ 个月后，Kymbrea 有 $30 + 2m$ 本漫画书，LaShawn 有 $10 + 6m$ 本。令 $10 + 6m = 2(30 + 2m)$ ，得到 $10 + 6m = 60 + 4m$ ，因此 $2m = 50$ ， $m = 25$ 。

所以正确答案是 E。

After $m$ months, Kymbrea has $30 + 2m$ comic books and LaShawn has $10 + 6m.$ Setting $10 + 6m = 2(30 + 2m)$ gives $10 + 6m = 60 + 4m,$ so $2m = 50$ and $m = 25.$

Thus, the correct answer is E.

2017 AMC 12B 第 1 题

答案：E

难度评级：920

解答：

其他年份的第 1 题