Question

油漆工 Paula 原本刚好有足够油漆粉刷 $30$ 间同样大小的房间。不幸的是，在去上班的路上，有三桶油漆从她的卡车上掉了下来，所以她剩下的油漆只够粉刷 $25$ 间房。她粉刷这 $25$ 间房用了多少桶油漆？

Paula the painter had just enough paint for $30$ identically sized rooms. Unfortunately, on the way to work, three cans of paint fell off her truck, so she had only enough paint for $25$ rooms. How many cans of paint did she use for the $25$ rooms?

$10$

$12$

$15$

$18$

$25$

答案：C

知识点：比与比例速率

难度评级：870

解答：

丢失的 $3$ 桶油漆本来可以粉刷 $30-25=5$ 间房，所以每间房需要 $\dfrac35$ 桶。

$25$ 间房需要 $\dfrac35\cdot25=15$ 桶油漆。

所以正确答案是 C。

The lost $3$ cans would have painted $30-25=5$ rooms, so each room takes $\dfrac35$ of a can.

For $25$ rooms she used $\dfrac35\cdot25=15$ cans.

Thus, the correct answer is C.

2009 AMC 10B 第 3 题

答案：C

难度评级：870

解答：

其他年份的第 3 题