maths question: ratio?

The ratio of books, fiction and non-fiction is 4:5.

4 portions of fiction is = 388 books

1 portion would be = 388/4

5 portions of non-fiction would be = 388/4 x5 = 485 non-fiction books.

Answer: 485 non-fiction books.

The ratio of fiction books to non-fiction books in a library is 4:5. If there are 388 fiction books,

Let number of non-fiction books are there in the library =x

then 4/5=388/x

→x=388×5/4=485

We are given that fiction books:non-fiction books=4:5

Therefore total number of books in ratio=4+5=9

Now 4/388=5/x

therefore 4x=388*5

x=(388*5)/4

x=485

Hope i was of some use to you and it was my pleasure answering your question.

total books =x

4x/9=388

4x=388*9

x=388*9/4

x=97*9=873

x=873-388=485