A milkman cheats his customer in two ways. He mixes 10% water in pure milk and increases the price of milk by 10% . He purchases 20 kg pure milk at a rate of Rs. 15 per kg. His total profit by selling it is -

Explanation:-

C.P. of 20 kg milk = Rs. (20 × 15) = Rs. 300
Quantity of water added = 10% of 20 kg = 2 kg
S.P. of 1 kg mixture = 110% of Rs. 15 = Rs. 16.50
S.P. of 22 kg mixture = Rs. (22 × 16.50) = Rs. 363
Profit = Rs. (363 - 300) = Rs. 63