Algebra word problems

Question

Frank and Robert have baseball card collections include both special and regular cards. Frank wants 5 of Roberts special cards, but agrees that each of those 5 cards is worth 3 of Frank's regular cards. Robert wants 2 of Frank's special cards and agrees that each of those cards is worth 4 Roberts regular cards. They also both agree that their regular cards are worth the same. If Frank and Robert both gets all the special cards that each of them wanted, how many extra regular cards did Frank have to give Robert?

Answer 1

 

Here is the answer. Please contact me if something is not clear:

 

Frank gets 5 of Roberts special cards. Each one of these special cards costs Frank 3 regular cards. Therefore, Frank has to give Roberts 15 of his regular cards.

 

Roberts wants 2 of Frank's special cards. Each of these special cards costs Roberts 4 regular cards. Hence, in order to get the 2 cards he wants, Roberts has to give Frank 8 regular cards.

 

In total, Frank has given 15 regular cards to Roberts and received from him 8 regular cards.

 

That is, Frank did give to Roberts 7 extra regular cards !