Question

Bella 从自己家出发，朝朋友 Ella 家走去。与此同时，Ella 从自己家骑自行车朝 Bella 家出发。她们都保持恒定速度，Ella 骑车速度是 Bella 步行速度的 $5$ 倍。两家相距 $2$ 英里，即 $10,560$ 英尺，Bella 每一步走 $2 \tfrac{1}{2}$ 英尺。到两人相遇时，Bella 会走多少步？

Bella begins to walk from her house toward her friend Ella's house. At the same time, Ella begins to ride her bicycle toward Bella's house. They each maintain a constant speed, and Ella rides $5$ times as fast as Bella walks. The distance between their houses is $2$ miles, which is $10,560$ feet, and Bella covers $2 \tfrac{1}{2}$ feet with each step. How many steps will Bella take by the time she meets Ella?

$704$

$845$

$1056$

$1760$

$3520$

答案：A

知识点：路程、速度与时间比与比例单位换算

难度评级：1210

视频讲解：

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文字解答：

Ella 每骑五英尺，Bella 走一英尺，所以相遇时 Bella 走了两家距离的 $\frac16$ 。因此 Bella 走了英尺。因为她每步走 $2.5$ 英尺，到相遇时她走了步。 $\dfrac16 \cdot 10560=1760$ $\dfrac{1760}{2.5} = 704$

所以正确答案是 A。

Since for every foot Bella walks, Ella rides 5 feet, we know that Bella will walk $\frac16$ of the distance between the two houses, and so she walks $\dfrac16 \cdot 10560=1760$ feet. Since she walks $2.5$ feet per step, she takes $\dfrac{1760}{2.5} = 704$ steps by the time she meets Ella.

Thus, A is the correct answer.

2018 AMC 8 第 17 题

答案：A

难度评级：1210

视频讲解：

文字解答：

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