Question

史蒂夫的空游泳池装满时可容纳 $24{,}000$ 加仑水。它将由 $4$ 根水管注水，每根水管每分钟供水 $2.5$ 加仑。装满史蒂夫的游泳池需要多少小时？

Steve’s empty swimming pool will hold $24{,}000$ gallons of water when full. It will be filled by $4$ hoses, each of which supplies $2.5$ gallons of water per minute. How many hours will it take to fill Steve’s pool?

$40$

$42$

$44$

$46$

$48$

答案：A

知识点：速率单位换算

难度评级：870

小提示：

先求四根水管合起来的注水速度

First find the combined filling rate of the four hoses.

大提示：

求出总分钟数后，再换算成小时

Convert minutes to hours after finding the total number of minutes.

解答：

$4$ 根水管合起来每分钟注入 $2.5 \cdot 4 = 10$ 加仑水。

要注满 $24{,}000$ 加仑，水管需要 $24{,}000 \div 10 = 2{,}400$ 分钟。

$2{,}400$ 分钟等于 $2{,}400 \div 60 = 40$ 小时。

所以正确答案是 A。

The $4$ hoses together fill the pool with $2.5 \cdot 4 = 10$ gallons of water per minute.

To fill $24{,}000$ gallons, it will take the hoses $24{,}000 \div 10 = 2{,}400$ minutes to fill the pool.

$2{,}400$ minutes is the same as $2{,}400 \div 60 = 40$ hours.

Thus, A is the correct answer.

2009 AMC 8 第 6 题

答案：A

难度评级：870

小提示：

大提示：

解答：

其他年份的第 6 题