弱弱地问到数学题GWD

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: D

我觉得是要选A呀，那个（2）能知道买多少吗？

咦，那这样不是要选A咯。。。。

单独这个条件能知道答案？？She bought an equal number of $0.15 stamps and $0.29 stamps

各各数字扩大100倍

单价15和29,总共440块

29这个数字很特殊，只有遇到5，10，15这样的数字，才能和15这个数字结合成整十的

一个一个代，看能不能使15块的这个邮票也是整数