Question

in a school library, the ratio of mathematics books to science books is the same as the ratio of science books to hindi books. if there are 450 science books and 300 hindi books, find the number of mathematics books

Answer 1

$$\begin{gathered} \mathrm{Let}\mathrm{the}\mathrm{number}\mathrm{of}\mathrm{Mathematics}\mathrm{books}=\mathrm{x} \\ \mathrm{Number}\mathrm{of}\mathrm{Science}\mathrm{books}=450 \\ \mathrm{Number}\mathrm{of}\mathrm{Hindi}\mathrm{books}=300 \\ \mathrm{Now},\mathrm{according}\mathrm{to}\mathrm{question}: \\ \frac{\mathrm{No}.\mathrm{of}\mathrm{Maths}\mathrm{books}}{\mathrm{No}.\mathrm{of}\mathrm{Science}\mathrm{books}}=\frac{\mathrm{No}.\mathrm{of}\mathrm{Science}\mathrm{books}}{\mathrm{No}.\mathrm{of}\mathrm{Hindi}\mathrm{books}} \\ \Rightarrow \frac{\mathrm{x}}{450}=\frac{450}{300} \\ \Rightarrow \mathrm{x}=\frac{450\times 450}{300}=675 \\ \mathrm{So},\mathrm{number}\mathrm{of}\mathrm{Mathematics}\mathrm{books}=675 \end{gathered}$$