Question

Ratio and proportions The library at school is organized by fiction and non fiction books. There are 3 non fiction books for every 7 fiction books. How many total books are there if the library has 240 non fiction books?

Answer 1

In the library there are in total 800 books.

Explanation:

The number of non fiction books = 3 for every 7 fiction books.

⇒Ratio of Non Fiction : Fiction books = 3 : 7

Now, The total Non fiction books in library = 240

Let the total number of fiction books in the library = m

⇒Ratio of Non Fiction : Fiction books in Library = 240 : m

Now, By THE RATIO OF PROPORTIONALITY:

`(3)/(7)   = (240)/(m)`

or,
`m= (240 * 7)/(3)  = 560`

⇒ m = 560

or, the number of fiction books in library = 560

So,the total number of books in library

= Fiction books + Non - fiction books

= 560 + 240 = 800

Hence, in the library there are in total 800 books.