A man spent 60% of his salary on household expenses, 20% of his salary on rent and out of remaining salary, he donated 80% to a trust. If he is left with Rs. 20,000, then what is his salary?

Correct option is B

Given:
Salary spent on household expenses = 60%
Salary spent on rent = 20%
Solution:
Let the total salary of the man be x
Salary spent on household expenses = 60% of x =$$x × \frac{60}{100}= \frac{3x}{5}$$​​
Salary spent on rent = 20% of x = $$x × \frac{20}{100}= \frac{x}{5}$$​​
Rest salary = $$x-(\frac{3x}{5}+\frac{x}{5})$$​​
​$$= x-(\frac{4x}{5})\\\ \\= \frac{5x-4x}{5}\\\ \\= \frac x5\\$$​​
Salary donates by the man = 80% of the remaining = $$\frac x5 × \frac{80}{100}=\frac{4x}{25}$$​​
Remaining salary $$= \frac x5- \frac {4x}{25}$$​​
​$$= \frac{5x- 4x}{25}= \frac x{25}$$​​
As per the question,
$$\frac{x}{25}$$​= 20,000
x= 20,000 ×25
x= 5,00,000
Thus, the salary of the man is Rs. 5,00,000.