Question

鸸鹋 Elmer 在乡村道路上相邻两根电线杆之间行走需要 $44$ 个等长步幅。鸵鸟 Oscar 用 $12$ 个等长跃步可以走完同一距离。电线杆等距排列，沿这条路第 $41$ 根电线杆与第一根电线杆的距离正好是一英里，即 $5280$ 英尺。Oscar 的一次跃步比 Elmer 的一步长多少英尺？

Elmer the emu takes $44$ equal strides to walk between consecutive telephone poles on a rural road. Oscar the ostrich can cover the same distance in $12$ equal leaps. The telephone poles are evenly spaced, and the $41$ st pole along this road is exactly one mile ( $5280$ feet) from the first pole. How much longer, in feet, is Oscar's leap than Elmer's stride?

$6$

$8$

$10$

$11$

$15$

答案：B

知识点：比与比例单位换算植树问题

难度评级：870

解答：

第 $1$ 根和第 $41$ 根之间有 $40$ 个间隔，所以相邻电线杆之间距离为英尺。 $5280 \div 40 = 132$

这说明 Elmer 的一步长为英尺。类似地，Oscar 的一步长为英尺。因此 Oscar 的跃步长 $11 - 3 = 8$ 英尺。 $132 \div 44 = 3$ $132 \div 12 = 11$

所以正确答案是 B。

There are $40$ gaps between the $1$ st and $41$ st pole, which means that the distance between consecutive poles is $5280 \div 40 = 132$ feet.

This means that each of Elmer's strides is $132 \div 44 = 3$ feet. Similarly, each of Oscar's leaps is $132 \div 12 = 11$ feet. This makes Oscar's leap $11 - 3 = 8$ feet longer.

Thus, B is the correct answer.

2021 AMC 10A Fall 第 6 题

答案：B

难度评级：870

解答：

其他年份的第 6 题