Question

Anna 和 Bella 正在一起庆祝生日。五年前，Bella 满 $6$ 岁时，她收到了一只刚出生的小猫作为生日礼物。今天两个孩子和这只小猫的年龄之和为 $30$ 岁。Anna 比 Bella 大几岁？

Anna and Bella are celebrating their birthdays together. Five years ago, when Bella turned $6$ years old, she received a newborn kitten as a birthday present. Today the sum of the ages of the two children and the kitten is $30$ years. How many years older than Bella is Anna?

$1$

$2$

$3$

$4$

$5$

答案：C

知识点：年龄问题一次方程

难度评级：720

解答：

Bella 五年前 $6$ 岁，所以现在 $11$ 岁。

小猫五年前刚出生，所以现在 $5$ 岁。

三者共有 $3$ 个年龄，总和为 $30$ ，所以 Anna 的年龄是 $30-5-11 = 14$

Anna $14$ 岁，Bella $11$ 岁，所以 Anna 大 $3$ 岁。

正确答案是 C。

If Bella was $6$ five years ago, then she is $11$ right now.

If the kitten was a newborn five years ago, then it is $5$ right now.

Since the sum of all $3$ ages is $30,$ Anna's age is $30-5-11 = 14$

Since Anna is $14$ and Bella is $11,$ she is $3$ years older than Bella.

Thus, the correct answer is C.

2022 AMC 8 第 5 题

答案：C

难度评级：720

解答：

其他年份的第 5 题