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.
GWD Ans: D
疑问1：只有（2）推不出来
疑问2：好像只需要（1）就可以得到。
0.15x+0.29y=4.40
其中x,y为正整数，可以得出x=y=10.
那位大虾讨论一下？ | 
