求教GWD数学2-Q22

czwuyi

题目如下：
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.
       
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

解析说道：

total money = K = 500,000
K = L(labor) + materials(M)
问是否profit会大于150,000
条件1) >> K = 3M >> 不充分
条件2) >> profit > L >> 不充分
由条件1和2
K = 3M >> M = 500,000 / 3 and L = 2/3*(500,000)
profit > L = 2/3*(500,000) > 150,000

我不明白的是，为什么profit不是包括在500000元里面的呢？求牛人解答！谢谢！·

ljy900922

請問一下, 在那裡可以找到gwd 數學解析?

徐小玉儿

设material 为X 那么labour就是2X 总的是3X的
那么利润利润是500000-3X
它说利润大于labour
那就是500000-3X>2X
X算出是<100000
那肯定就是小于150000

whc583955

没仔细看题目..不过觉得可能楼主的问题在于对于profit这个词义的理解上?

简单说就是这样：cost是成本，revenue是销售额，profit是利润。而利润等于销售额减去成本。

ljy900922

But if material is less than 100,000, we still cannot derive whether profit is larger than 150,000 based on the relationship that profit is larger than cost of labour.

奔跑的蛋儿

楼主这个题是选E吗

irvan

w=500000，C=X（material）+2X（labor），R=500000-3X
因为R＞labor，既500000-3X＞2X，
所以C=3X＜300000，所以R=W-C＞200000＞150000
所以选C

wisdommingli

LS是对的

czwuyi

ljy900922 发表于 2013-7-13 14:46
請問一下, 在那裡可以找到gwd 數學解析?

你直接用论坛的搜索功能就OK啦

czwuyi

ljy900922 发表于 2013-7-13 15:00
But if material is less than 100,000, we still cannot derive whether profit is larger than 150,000 b ...

DS问题只需回答能否得解就可以了，这题可以解出来，所以选C。