请教几道问题

lasiaberyl

Q6:

The ratio of the number of red cars in a certain parking lot to the number of black cars is 3 to 8.  If there are 72 black cars in the lot, how many red cars are there in the lot?

 

A.     11

B.     15

C.     24

D.     27

E.      32

Answer:c

Q7:

What is the value of │x + 7│?

(1)     │x + 3│= 14

(2)     (x + 2)² = 169

                  
                        

 

 

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: d

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：a

 

lasiaberyl

这个应该不是答案错了吧，nn帮忙看下！

蓝汐冰剑

我的答案是1.D 2.C

最后一题是A，因为要买4.4元的邮票只可能两种各买10张，我是代了3个数字一个个进去算的，不知道有没有更简单的方法

等待NN