2017 AMC 10A 第 2 题

Question

Pablo 给朋友们买冰棒。商店出售单支冰棒，每支

\$1

；

3

支装盒子，每盒

\$2

；

5

支装盒子，每盒

\$3

。Pablo 用

\$8

最多可以买多少支冰棒？

Pablo buys popsicles for his friends. The store sells single popsicles for

\$1

each,

3

-popsicle boxes for

\$2

each, and

5

-popsicle boxes for

\$3.

What is the greatest number of popsicles that Pablo can buy with

\$8?

8

11

12

13

15

答案：D

知识点：钱币最优化

难度评级：770

小提示：

比较三种购买方式每美元能买到的冰棒数。

Compare popsicles per dollar for the three buying options

大提示：

先决定

\$6

最划算的花法，再花剩下的

\$2

。

First decide the best use of

\$6

, then spend the remaining

\$2

解答：

五支装盒子最划算，

\$3

可以买五支。

用六美元买两盒，可得

5 \cdot 2 = 10

支，还剩

\$8 - \$6 = \$2

。

\$1

的单支冰棒最不划算，所以剩下的钱应买一个

3

支装盒子。

总数为

10 + 3 = 13

。

所以正确答案是 D。

The

\$3

boxes give us the most popsicles per dollar, so we want to buy as many of those as possible.

We can buy two of those, getting

5 \cdot 2 = 10

popsicles with

\$8 - \$6 = \$2

remaining.

The

\$1

single popsicles are the worst deal, so Pablo should spend the rest of his money on the

3

-popsicle box.

He then ends up with

10 + 3 = 13

popsicles.

Thus, D is the correct answer.

2017 AMC 10A 第 2 题

答案：D

难度评级：770

小提示：

大提示：

解答：

其他年份的第 2 题