AMC 8 2011 Problem 5
AMC8 2011 年第 5 题
表达式与运算★★☆☆☆
What time was it 2011 minutes after midnight on January 1, 2011?
从 2011 年 1 月 1 日凌晨开始，经过 2011 分钟后是什么时间？
| 1 月 1 日下午 9:31 | 1 月 1 日下午 11:51 | 1 月 2 日上午 3:11 | 1 月 2 日上午 9:31 | 1 月 2 日下午 6:01
- A. / 1 月 1 日晚上 9:31
- B. / 1 月 1 日晚上 11:51
- C. / 1 月 2 日凌晨 3:11
- D. / 1 月 2 日上午 9:31
- E. / 1 月 2 日下午 6:01
正确答案 · Correct Answer
D
解析 · Solution
Solution 1
There are 60 minutes in an hour. , or 33 hours and 31 minutes. There are 24 hours in a day, so the time is 9 hours and 31 minutes after midnight on January 2, 2011. January 2 at 9:31AM.
Like the previous solution, 2011 minutes is 33 hours and 31 minutes. That means it has to be January 1 at 9:31PM or January 2 at 9:31AM because they are the only ones that end with 31. But the answer can't be January 1 because there are 24 hours in a day and 33 is greater than 24. So the answer is January 2 at 9:31AM.
The answer choices are relatively far apart, so we can use estimation. minutes is around 33.5 hours, or about 1.5 days. The only answer choice around 1.5 days from the midnight of January 1, 2011 is January 2 at 9:31AM.
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