Question

邮差 Pete 有一个计步器来记录步数。计步器最多显示 $99999$ 步，下一步会翻转为 $00000$ 。Pete 计划计算自己一年的里程。一月 $1$ 日，Pete 将计步器设为 $00000$ 。一年中，计步器从 $99999$ 翻到 $00000$ 共四十四次。十二月 $31$ 日，计步器显示 $50000$ 。Pete 每英里走 $1800$ 步。以下哪一项最接近 Pete 这一年走的英里数？

Postman Pete has a pedometer to count his steps. The pedometer records up to $99999$ steps, then flips over to $00000$ on the next step. Pete plans to determine his mileage for a year. On January $1$ Pete sets the pedometer to $00000.$ During the year, the pedometer flips from $99999$ to $00000$ forty-four times. On December $31$ the pedometer reads $50000.$ Pete takes $1800$ steps per mile. Which of the following is closest to the number of miles Pete walked during the year?

$2500$

$3000$

$3500$

$4000$

$4500$

答案：A

知识点：位值单位换算估算

难度评级：1070

解答：

每次翻转计 $100000$ 步，所以 Pete 共走了 $44\cdot 100000+50000=4{,}450{,}000$ 步。

除以 $1800$ ，约为 $2472$ 英里，最接近 $2500$ 。

所以正确答案是 A。

Each flip counts $100000$ steps, so Pete took $44\cdot 100000+50000=4{,}450{,}000$ steps.

Dividing by $1800$ gives about $2472$ miles, which is closest to $2500.$

Thus, the correct answer is A.

2008 AMC 10B 第 12 题

答案：A

难度评级：1070

解答：

其他年份的第 12 题