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标题: [求助] 两道 DS 题 [打印本页]

作者: cathy0929 时间: 2008-9-19 23:49
标题: [求助] 两道 DS 题

1. A construction company was paid a total of $500,000 for a construction project. The company’s only costs for the project were for labor and materials. Was the company’s profit for the project greater than $150,000?

(1) the company’s total cost was three times its cost for materials

(2) the company’s profit was greater than its cost for labor

这种文字转换题是我的弱项，
答案选择C，
烦请大家给我解释一下，谢谢

2. A contractor combined X tons of a gravel mixture that contains 10 percent gravel G, by weight, with Y tons of a mixture that contains 2 percent gravel G, by weight, to produce Z tons of a mixture that was 5 percent gravel G, by weight. What is the value of X?

(1) Y=10

(2) Z=16

答案选择D，
我列了一个等式，应该是必须Y,Z两个量知道了才行，不知道为什么是D。谢谢大家的解释

作者: yunlinli 时间: 2008-9-20 02:51
1. Total cost (TC)= 3 cost of materials (MC) or 1MC and 1 cost of labor
(LC), which equals to 2 MC. Nothing said about profit, so insuff.

2. Nothing about MC, so insuff.



Together. Let's find MC. Costs+profit=500000

Only cost for labor and materials. Cost of Labor(LC)=2MC and profit is greater than LC or 2 MC

1MC+2MC+2MC=500000    5MC=500000 MC=100000

Profit not less than 200000.  Answer is C.

第二道是什么意思呢？ G是定量？

作者: cathy0929 时间: 2008-9-20 15:10

yunlinli，thank you very much, your explanation is very clear.

第二题我自己根据最终混合物的combination情况列了一个有关X,Y,Z的等式，因为没有Y和Z之间的关系，所以答案最后选择D，我实在不能理解。

大牛们，烦请解释一下吧

作者: cathy0929 时间: 2008-9-20 17:45

知道的大牛们解释一下吧，谢谢

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