A shopkeeper bought some mangoes at a rate of 9 per Rs.5 and then sold them at a rate of dozen per Rs. 8. Find his percentage of profit and loss.
20%
Cost price of 9 mangoes = Rs. 5
Selling Price of 12 mangoes = Rs.8
So, selling price of 1 mango = Rs.812 = Rs. 0.66
Selling price of 9 mangoes = Selling price of 1 mango x 9 = 0.66 x 9 = Rs. 6
SP > CP, so it is profit
Profit = Selling Price - Cost Price = Rs.6 - 5 = Rs. 1
Profit% = profitC.P x 100 = 15 x 100 = 20%