The ratio of all books to used books is 17;9.
The ratio of new books to used books is 8;9.
What are the ratio and proportion?
Proportion is an equation that defines that the two given ratios are equivalent to each other.
While ratios help us understand the relation between two different quantities, proportion helps us understand the relationship between two ratios.
There are 17 books on a shelf 8 of these books are new.
The ratio of all books to used books is;
[tex]\rm Ratio=\dfrac{All \ book }{New \ book }\\\\Ratio=\dfrac{17}{17-8}\\\\Ratio=\dfrac{17}{9}[/tex]
The ratio of all books to used books is 17;9.
The ratio of new books to used books is;
[tex]\rm Ratio=\dfrac{New\ book }{Total \ book- New \ book }\\\\Ratio=\dfrac{8}{17-8}\\\\Ratio=\dfrac{8}{9}[/tex]
The ratio of new books to used books is 8;9.
Learn more about ratios here;
https://brainly.com/question/374016
#SPJ2
