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?
Correct Answer: Rs. 2525
Explanation:
Let his income be Rs. N, then N - 5% of N - 20% of 95% of N = 1919
⇒ N - N/20 - (20 x 95 x N)/(100 x 100) = 1919
⇒ N - N/20 - 19N/100 = 1919
⇒ 100N - 5N - 9N = 191900
∴ N = 191900 / 76 = 2525
