A milkman has 20 liters of milk. If he mixes 5 liters of water, which is freely available, in 20 liters of pure milk. If the cost of pure milk is Rs. 18 per litre, then the profit of the milkman, when he sells all the mixture at  cost price, is:
20%
25%
27%
18%
33.33%
Total cost of pure milk =
Now 5 litres of water added and sell at CP
Then SP=
P%= = 25%