Given is the number of science fiction books = 48
Let the number of mystery books be = x
Let the number of biographies be = y
Ratio of the number of mystery books to the number of science fiction books is 4:3 so [tex]\frac{4}{3}= \frac{x}{48}[/tex]
=[tex]3x=48\times4[/tex]
[tex]x=64[/tex]
Ratio of the number of science fiction books to the number of biographies is 4:5 so [tex]\frac{4}{5}=\frac{48}{y}[/tex]
=[tex]4y=5\times48[/tex]
[tex]y=60[/tex]
Hence there are 48 science fiction books, 64 mystery books and 60 biographies.
So total number of books are = [tex]48+64+60=172[/tex]
