Question

in a library the ratio of mathematics books to science is the same as the ratio of science books to hindi books . if there are 900 books of science and 600 of hindi find the number of books in mathematics

Answer 1

Let the number of Mathematics books be 'x'.
Given, the ratio of Mathematics books to Science books is the same as the ratio of Science books to Hindi books.
i.e. x:900=900:600
     x/900=900/600
     x/900=3/2
     2x=2700  Therefore x = 1350
There are 1350 books of Mathematics.