At a book store there are 25 books on the clearance section. 20 of the books are young adult novels and the rest of the books are picture books. Which statement is not true?

For every 4 young adult novels, there is 1 picture book
For every 5 books, 4 are young adult novels
The ratio of picture books to young adult novels is 1:4
There is 1 picture book for every 5 books
All statements are true