2013 AMC 10A 第 5 题

Question

Tom、Dorothy 和 Sammy 一起度假，并同意平均分摊费用。旅途中 Tom 支付了

\$105

，Dorothy 支付了

\$125

，Sammy 支付了

\$175

。为了平均分摊，Tom 给 Sammy

t

美元，Dorothy 给 Sammy

d

美元。

t-d

是多少？

Tom, Dorothy, and Sammy went on a vacation and agreed to split the costs evenly. During their trip Tom paid

\$105,

Dorothy paid

\$125,

and Sammy paid

\$175.

In order to share costs equally, Tom gave Sammy

t

dollars, and Dorothy gave Sammy

d

dollars. What is

t-d?

15

20

25

30

35

答案：B

知识点：平均数钱币

难度评级：900

小提示：

先求总费用和每个人应承担的份额。

First find the total trip cost and each person’s fair share

大提示：

Tom 和 Dorothy 各把低于应付份额的差额给 Sammy。

Tom and Dorothy each pay Sammy the amount they are short of a fair share

解答：

总费用为

\$105+\$125+\$175=\$405

，所以每人应承担

\$405\div3=\$135

。

Tom 少付

\$30

，Dorothy 少付

\$10

，因此

t=30

且

d=10

。

所以

t-d=30-10=20

。

所以正确答案是 B。

The total cost was

\$105+\$125+\$175=\$405

, so each person’s share was

\$405\div3=\$135

.

Tom paid

\$30

less than his share, and Dorothy paid

\$10

less than her share, so

t=30

and

d=10

.

Therefore

t-d=30-10=20

.

Thus, B is the correct answer.

2013 AMC 10A 第 5 题

答案：B

难度评级：900

小提示：

大提示：

解答：

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