Please help...it's been a long time since I've had to do one of these?

Question

Charles had 336 local stamps and foreign stamps at first.

He gave away 2/5 of his local stamps and 46 foreign stamps.

He then found that he had 3/5 as many local stamps as foreign stamps left. How many foreign stamps did Charles have at first?

Answer 1

let L = local stamps and F = foreign stamps

L + F = 336

Charles give some away and so now has L - 2/5 and F - 46

He discovers that his local stamps (L - 2/5) equals 3/5 of his foreign stamps (= 3/5 (F - 46))

(L - 2/5) = 3/5(F - 46)

3/5 L = 3/5(F - 46)

multiplying both sides by 5/3 to get rid of fraction...

L = F - 46

substituting back into original equation

F-46 + F = 336

2F = 336 + 46

F = 382/2

F = 191

L = 336 - 191 = 145

Answer 2

He had L local stamps and F foreign stamps.

L + F = 336

After he gave some away, he had

(3/5) * L  and  F-46 left

what he noticed was that

(3/5) * ((3/5) * L) = F-46

So you have two equations with two variables.  Substitute and solve.