牛人帮我看看GWD5的一道数学，十分感谢

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.

 0.15*X+0.29*Y=4.4  即15X+29Y=440

因为同时要找15与29的倍数，假设Y=5,10,15(15 就不可以了因为15*29=435；再看5*29=145，440-145=295，而295/15=19.667，所以只有10了，当Y=10,X也=10。所以选A.

我解释的可能不是很好，希望能帮上忙。

谢谢纠正

GWD1里同样的这道题答案给的是D....汗了