Question

A milkman has 20 litres of milk. If he mixes 5 litres of water which is freely available, in 20 litres 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:

• A. 20%
• B. 25%
• C. 33.33%
• D. 18%

Answer 1

The correct option is B 25%

When the water is freely available and all the water is sold at the price of the milk, then the water gives the profit on the cost of 20 litres of milk.
Therefore, profit % $=\frac{profit}{costprice}\times 100$
profit percentage $=\frac{5}{20}\times 100=25\%$

NOTE:
Here the milkman cheats his customer by a false practice of
creating an illusion that instead of 20 litres milk, there is 25 litres of milk. So this extra 5 litres of milk (actually water) is the part of the profit.