Answer:
150
Step-by-step explanation:
The ratio is 3:5, so you can make this equation:
[tex]3x+5x=240[/tex], because for any integer x, the ratio will stay the same.
solve that:
[tex]3x+5x=240\\8x=240\\x=30[/tex]
We're not down yet!
we need to find 5x, not x.
[tex]5*30=150[/tex]
There are 150 non-fiction books in the library.
check!
150+90=240