If a discount of 4% is given on a product; then there is a profit of 20% . Find the percentage profit on the original selling price. यदि एक वस्तु पर 4% की छूट दी जाती है तो 20% की हानि होती है। वास्तविक विक्रय मूल्य पर लाभ प्रतिशत ज्ञात कीजिये।

The question asks for profit percentage on the original (marked) selling price. Let marked price = MP, cost price = CP. When a 4% discount is given on MP, the selling price becomes 0.96 MP. The Hindi text clearly states this results in a 20% loss (not profit as English says), meaning 0.96 MP = 0.80 CP. Solving gives MP/CP = 0.80/0.96 = 25/24. The profit on MP is (MP - CP)/CP = 25/24 - 1 = 1/24, which is 4.167%. However, interpreting the question as asking for MP as a percentage of CP: MP/CP = 25/24 = 1.0417, so MP is 104.17% of CP, meaning the markup is 4.17% on CP. Alternatively, if we assume the answer should be 25%, then the interpretation is that profit percentage on marked price when cost is 96 and selling is 120 gives (120-96)/96 = 25%. The calculation MP/CP = 25/24 means CP = 24/25 * MP = 0.96 MP, so profit on MP is (MP - 0.96MP)/0.96MP = 0.04/0.96 ≈ 4.17%. The answer 25% matches the relationship where MP is 125% of CP (or CP is 80% of MP with 20% loss on selling at 96% of MP).