There are 14 books on a shelf. 5 of these books are new.

(a) What is the ratio of new books to used books?

(b) What is the ratio of all books to used books?

Number of books on the shelf = 14

Number of books that are new = 5

Number of books that are old = (14 - 5)

= 9

a) The ratio of the new books to the old books = 5:9

So we come to know that the ratio of the number of new books to the number of old books is 5:9 and it is not possible to simplify it further.

b) The ratio of all books to the used books = 14:9

This is also a ratio that cannot be further simplified. So the ratio of the total number of books to the number of used or old books can be represented by 14:9.