taotao数学30套中不会做的题

第一套：

Q14:

If 10⁵⁰ – 74 is written as an integer in base 10 notation, what is the sum of the digits in that integer?

A.      424

B.      433

C.      440

D.      449

E.      467

Answer:

“in base 10 notation”是什么意思啊？

Q30:

Joanna bought only $0.15 stamps and $0.29 stamps.  How many $0.15 stamps did she buy?

(1)     She bought $4.40 worth of stamps.

(2)     She bought an equal number of $0.15 stamps and $0.29 stamps.

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.

Answer:

答案给的是Ｄ，我咋觉得选Ａ呢？仅根据条件（２）能解除这道题来吗？

第二套：

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.

Answer:

答案选Ｃ我选Ｅ……

1.理解成十进制就行.

2. 1)公司的总成本是材料成本的三倍.可以推出材料成本是1/3总成本,人工成本是2/3总成本.

2)公司利润比人工成本大.

合起来看,知道了人式成本(2/3乘以500000),公司利润比人工成本都大,肯定是大于150000了.所以选C.