To increase the sales, a shopkeeper gives40% discount on the goods. There was a rise of 120% in sales. Find % change in revenue

Let the price of goods before discount be P and the number of goods sold be N. So, total revenue = PN
Price after discount = 6P/10 = 3P/5 and number of goods sold = 22N/10 = 11N/5. Total revenue = 3P/5 * 11N/5 = 33/25 PN
Percentage change in revenue = (33/25 - 1)*100% = 32%

32%