2013 AMC 12B 第 2 题

Question

Green 先生通过沿着长方形花园的两条边走路来测量花园，发现它是

15

步乘

20

步。他每一步长

2

英尺。Green 先生预计花园每平方英尺能产半磅土豆。他预计花园能产多少磅土豆？

Mr. Green measures his rectangular garden by walking two of the sides and finds that it is

15

steps by

20

steps. Each of Mr. Green’s steps is

2

feet long. Mr. Green expects a half a pound of potatoes per square foot from his garden. How many pounds of potatoes does Mr. Green expect from his garden?

600

800

1000

1200

1400

答案：A

知识点：单位换算面积速率

难度评级：1020

小提示：

先把步数换算成英尺：每步

2

英尺。

Convert steps to feet first: each step is

2

feet

大提示：

将平方英尺面积乘以每平方英尺

\dfrac12

磅。

Multiply the area in square feet by

\dfrac12

pound per square foot

解答：

花园的长和宽分别为

2\cdot 15 = 30

英尺和

2\cdot 20 = 40

英尺，面积为

1200

平方英尺。每平方英尺能产半磅土豆，所以预计产量为

\tfrac12\cdot 1200 = 600

磅。正确答案是 A。

The garden is

2\cdot 15 = 30

feet by

2\cdot 20 = 40

feet, an area of

1200

square feet. At half a pound per square foot, Mr. Green expects

\tfrac12\cdot 1200 = 600

pounds. Thus, the correct answer is A.

2013 AMC 12B 第 2 题

答案：A

难度评级：1020

小提示：

大提示：

解答：

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