The sum of cost price and marked price of article 'A' and that of article 'B' are Rs. 13,200 and Rs. 15,000, respectively. Articles 'A' and 'B' were marked 20% and 100% above their respective cost prices. If both the articles were sold after allowing a discount of 10%, then find the difference between their selling prices.

Let the cost price of article 'A' be Rs. 'x' Therefore, marked price of article 'A' = 1.20 × x = Rs. '1.2x' According to the question, 1.2x + x = 13200 Or, 2.2x = 13200 Or, x = (13200 / 2.2) = 6000 Marked price of article 'A' = 1.2 × 6000 = Rs. 7200 Selling price of article 'A' = 0.9 × 7200 = Rs. 6480 Similarly, let the cost price of article 'B' be Rs. 'y' Marked price of article 'B' = 2y y + 2y = 15000 Or, 3y = 15000 Or, y = (15000 / 3) = 5000 Marked price of article 'B' = 2 × 5000 = Rs. 10000 Selling price of article 'B' = 0.9 × 10000 = Rs. 9000 Required difference = 9000 − 6480 = Rs. 2520