Can someone please explain to me how to work this out? It costs 40c for a postcard stamp and 45c to mail a letter. Susan wrote to 8 friends and the stamps cost $3.45. How many letters did she send?

Question

anonymous · Answer

divide 3.45 by 40 and get 8.625. So she sent about9 letters. Im sure that's how you do if, sorry if im wrong.

sepeario · Answer

Sorry, the answer is 5.

anonymous · Answer

@hannalynn11
How did you get the number 40?

sepeario · Answer

40c.

anonymous · Answer

But it costs 45c to sent the letter ?

sepeario · Answer

but stamps are 40c.

anonymous · Answer

I'm saying the way she did it is wrong.

anonymous · Answer

.85 times 4=3.4

sepeario · Answer

still wrong, the answer is 5.

anonymous · Answer

If he is only paying for stamps (eve number), then how did he get odd amount of money paid ($3.45). Unless there is tax involved.

sepeario · Answer

lol ok thanks i think the book is wrong.

anonymous · Answer

Are you sure you did not copy it down wrong?

sepeario · Answer

Just wait ill check.

sepeario · Answer

Its still five. Although I think the book has a error. Some other questions were wrong too.

directrix · Answer

@Sepeario 

P + L = 8 where P is the number of cards; L, the number of Letters
.40P + .45L = 3.45

Solving these gives an approx of 5 for L.