Milk contains 5% water.What quantity of pure milk should be added to 10 litres of milk to reduce this to 2% ?
Choose the correct choice from the following answers: A) 5 litres B) 7 litres C) 15 litres D) can not be determined E) none of these

Rationale: "here required quantity of pure milk = 10 × ( 5 − 2 ) / 2 = 10 × 3 / 2 = 15 litres . answer c"
Answer: C