TT-2-22

Q22:

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.

答案是C,没想明白怎么能解出来的，谢谢！

题意：500是总收入，profit=500-（labor + materials），问能否确定 profit比150大

（1）labor+materials=3倍的materials，即materials=1/2 labor

（2）profit>labor

（1）（2）单独显然无法确定

结合两个条件，由profit=500-（labor + materials），得labor + materials=500-profit，所以1.5 倍labor=500-profit，又由于1.5profit>1.5labor，所以1.5profit>500-profit，即2.5profit>500,得profit>200，能确定profit>150

故选 c