Question

一辆车的五个轮胎（四个行驶轮胎和一个全尺寸备胎）进行轮换，使得汽车行驶前 $30{,}000$ 英里期间每个轮胎使用的里程数相同。每个轮胎使用了多少英里？

The five tires of a car (four road tires and a full-sized spare) were rotated so that each tire was used the same number of miles during the first $30{,}000$ miles the car traveled. For how many miles was each tire used?

$6000$

$7500$

$24{,}000$

$30{,}000$

$37{,}500$

答案：C

知识点：速率

难度评级：980

解答：

在 $30{,}000$ 英里的行驶中，始终有 $4$ 个轮胎在使用，所以总轮胎里程为 $4 \times 30{,}000 = 120{,}000$ 轮胎英里。

平均分给 $5$ 个轮胎，每个轮胎使用 $\dfrac{120{,}000}{5} = 24{,}000$ 英里。

所以正确答案是 C。

During the $30{,}000$ miles, $4$ tires are always in use, so the total tire-mileage is $4 \times 30{,}000 = 120{,}000$ tire-miles.

Split equally among $5$ tires, each tire is used $\dfrac{120{,}000}{5} = 24{,}000$ miles.

Thus, the correct answer is C .

1992 AMC 8 第 12 题

答案：C

难度评级：980

解答：

其他年份的第 12 题