Question

A man donated 5% of his income to a charitable organisation and deposited 20% of the remainder in a bank. If he now has Rs. 1919 left, what is his income ?

Answer 1

Let the income be x

By condition,
$x \times \frac{100 - 5}{100} \times \frac{100 - 20}{100} = 1919 \\ x \times \frac{95}{100} \times \frac{80}{100} = 1919 \\ x \times 0.95 \times 0.80 = 1919 \\ x \times 0.76 = 1919 \\ x = \frac{1919}{0.76} \\ x = 2525$

Answer 2

Hello!

Let his income be $\bf{x}$.

ATQ,

$\bf{x} \sf \:x\: \dfrac{\sf 100-5}{\sf 100} \sf \:x\: \dfrac{\sf 100-20}{\sf 100} = \sf 1919$

⇒ $\bf{x} \sf \:x\: \dfrac{\sf 95}{\sf 100} \sf \:x\: \dfrac{\sf 80}{\sf 100} = \sf 1919$

⇒ $\bf{x} \sf \:x\: \sf 0.95 \sf \:x\: \sf 0.80 = \sf 1919$

⇒ $\bf{x} \sf \:x\: \sf 0.76 = \sf 1919$

⇒ $\bf{x} = \dfrac{\sf 1919}{\sf 0.76} = \boxed{\sf 2525}$

Hence,
The man's income is $\bf{Rs.\: 2525}$

Cheers!