DS 問題!!

treewing929

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.

請問為什麼是 C?
我只想到這些:
500,000 - total cost = profit
total cost = labor cost + material cost
Q: profit > 150,000? = 500,000 - tc >150,000 = tc<350,000?
1) tc = 3M = M + L
So L = 2M
2) profit > L

謝!!

linchaoyi

TC=LC+MC=3X
P>LC所以P>2X
3x+P=500可知5x<500
有3x<300，所以P>200...
不知道这么做对不对。。

treewing929

TC=LC+MC=3X
P>LC所以P>2X
3x+P=500可知5x<500
有3x<300，所以P>200...
不知道这么做对不对。。

-- by 会员 linchaoyi (2012/2/28 21:06:10)

明白!! 沒有想到中間! 謝謝你!!