Two friends, Alex and Bob, go to a bookshop, together with their sons Peter and Tim. All four of them buy some books. Each book costs a whole amount of shillings.

When they leave the shop, they notice that both fathers have spent 21 shillings more than their respective sons. Moreover, each of them paid per book the same amount of shillings as the number of books that he bought.

The difference between the number of books that Alex bought and that Peter bought is five.

Who is the father of Tim?

(In reply to Answer by Julie)

I do not agree.  If they were to say "Two friends, Alex and Bob, go to a bookshop, together with their sons Peter and Tim, respectively,"   then you could make that statement.  In this case the respective sons just refers back to whichever one is their father.

Posted by john on 2005-03-11 18:51:52