Question

A man spends 20% of his salary on house rent. After spending 25% of the remainder he has Rs. 4800 left. What is his monthly salary?

Answer 1

$$\begin{gathered} \mathrm{Let}\mathrm{the}\mathrm{monthly}\mathrm{salary}\mathrm{of}\mathrm{a}\mathrm{man}=\mathrm{Rs}x \\ \mathrm{Amount}\mathrm{spent}\mathrm{on}\mathrm{house}\mathrm{rent}=20\%\mathrm{of}\mathrm{Rs}x=\frac{20}{100}x=\mathrm{Rs}\frac{x}{5} \\ \mathrm{Remaining}\mathrm{amount}=\mathrm{Rs}\left(x-\frac{x}{5}\right)=\mathrm{Rs}\frac{4}{5}x \\ \mathrm{Amount}\mathrm{spent}\mathrm{again}=25\%\mathrm{of}\mathrm{remaining} \\ =\frac{25}{100}\times \frac{4}{5}x \\ =\mathrm{Rs}\frac{1}{5}x \\ \mathrm{then},\mathrm{remaining}\mathrm{amount}=\mathrm{Rs}\left(\frac{4}{5}x-\frac{1}{5}x\right)=\mathrm{Rs}\frac{3}{5}x \\ \therefore \frac{3}{5}x=4800 \\ x=4800\times \frac{5}{3} \\ x=1600\times 5 \\ x=\mathrm{Rs}8000 \\ \therefore \mathrm{his}\mathrm{monthly}\mathrm{salary}\mathrm{is}\mathrm{Rs}8000. \end{gathered}$$