Question

Wen 家三代人去看电影，每一代有两人。最年轻一代的两人作为儿童享受 $50\%$ 折扣。最年长一代的两人作为老人享受 $25\%$ 折扣。中间一代的两人没有折扣。Wen 祖父的一张老人票价为 $\$6.00$ ，他要为所有人付钱。他一共要付多少美元？

Three generations of the Wen family are going to the movies, two from each generation. The two members of the youngest generation receive a $50\%$ discount as children. The two members of the oldest generation receive a $25\%$ discount as senior citizens. The two members of the middle generation receive no discount. Grandfather Wen, whose senior ticket costs $\$6.00,$ is paying for everyone. How many dollars must he pay?

$34$

$36$

$42$

$46$

$48$

答案：B

知识点：百分数逆推法

难度评级：1060

小提示：

老人票是全价的 $75\%$ ，所以先求全价。

A senior ticket is $75\%$ of the full price, so find the full price first

大提示：

加上两张老人票、两张全价票和两张儿童票。

Add two senior, two full, and two child tickets

解答：

老人票价为 $\$6$ ，这是全价的 $\dfrac34$ ，所以全价票为 $\dfrac43 \cdot 6 = \$8$ ，儿童票为 $\dfrac12 \cdot 8 = \$4$ 。

总价为 $2(6 + 8 + 4) = \$36\text{。}$

所以正确答案是 B。

The senior ticket costs $\$6,$ which is $\dfrac34$ of the full price, so a full ticket costs $\dfrac43 \cdot 6 = \$8,$ and a child ticket costs $\dfrac12 \cdot 8 = \$4.$

The total is $2(6 + 8 + 4) = \$36.$

Thus, the correct answer is B.

2009 AMC 10A 第 8 题

答案：B

难度评级：1060

小提示：

大提示：

解答：

其他年份的第 8 题