AMC8 2012

AMC8 2012 · Q2

AMC8 2012 · Q2. It mainly tests Averages (mean), Arithmetic misc.

In the county of East Westmore, statisticians estimate there is a baby born every 8 hours and a death every day. To the nearest hundred, how many people are added to the population of East Westmore each year?

在 East Westmore 县，统计学家估计每 8 小时出生一个婴儿，每天死亡一人。每年 East Westmore 人口增加多少人？（四舍五入到百位）

(A) 600 600

(B) 700 700

(D) 900 900

(E) 1000 1000

Answer

Correct choice: (B)

正确答案：（B）

Solution

There are $24\text{ hours}\div8\text{ hours} = 3$ births and one death everyday in East Westmore. Therefore, the population increases by $3$ - $1$ = $2$ people everyday. Thus, there are $2 \times 365 = 730$ people added to the population every year. Rounding, we find the answer is $\boxed{\textbf{(B)}\ 700}$.

East Westmore 每天有 $24\text{小时}\div8\text{小时}=3$ 个出生和 1 个死亡。因此，人口每天增加 $3-1=2$ 人。所以，每年增加 $2\times365=730$ 人。四舍五入，答案是 $\boxed{\textbf{(B)}\ 700}$。

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