How much water must be added to a bucket which contains 40 liters of milk at the cost price of Rs.3.50 per liter so that the cost of milk reduces to Rs.2 per liter?
Answer: C
Total cost price =Rs(40 x 7/2) = Rs.140
Cost per litre =Rs.2,
Total quantity = 140/2 = 70 Litres.
Water to be added =(70-40) =30 Litres.