Article 1 is sold for ₹180. Article 2 is sold for ₹240. The profit on article 1 is 20% and loss on article 2 is 20%, What is the sum of cost prices of the two articles?

₹450

Selling price of article 1 = Rs. 180

The profit on article 1 = 20%

180 = cost price × 120%

Cost price = Rs.150

Selling price of article 2 = Rs. 240

The loss on article 2 = 20%

240 = cost price × 80%

Cost price = Rs. 300

⇒ The sum of cost prices of the two articles = 150 + 300 = Rs. 450