Question

A father gives $1\%$ of his monthly salary to his two sons as pocket money. The elder son gets $80\%$ of the total amount given to the two sons and he spends $80\%$ of his salary. If he saves Rs. $20$ every month, then the monthly salary of the father is

• A. Rs. $10000$
• B. Rs. $11500$
• C. Rs. $12000$
• D. Rs. $12500$

Answer 1

Answer: (D)

Rs. $12500$

Let the father's salary be Rs. $x$.

Then part of salary given to the two sons as pocket money $=\frac{x}{100}$
Share of the elder son $=\frac{80}{100}\times \frac{x}{100}=\frac{4x}{500}$
Expenditure of the elder son $=\frac{80}{100}\times \frac{4x}{500}=\frac{16x}{2500}$
$\therefore$ Savings of the elder son $=\frac{4x}{500}-\frac{16x}{2500}=\frac{4x}{2500}$
Given, $\frac{4x}{2500}=$ Rs. $20$

$\Rightarrow x=$ Rs. $\frac{20\times 2500}{4}$

$\Rightarrow x$ $=$ Rs. $12500$