GWD-1（共31套）一道数学题，大家帮忙看看是否答案有问题？多谢！

Lofire

我的分析是这样的：分设0.15的a张，0.29的b张，那么

（1）可得15a + 29b = 440，由于15和440都可以被5整除，因此b必然可以被5整除，于是用b=0,5,10,20分别代入，只有b=10可以，b=20则超过440了。

（2）只说明a和b相同，那如何能确定a具体的值呢？因此，我认为不充分。

综上，我选择A。

小籹子

我怎么觉得选择B呢，两个都买的一样就是一个十张看都看的出来的，而A里面的话每样买十张和买0.29五张买0.15十九张都符合啊

Lofire

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.

给的答案是：D

我的答案是：A