how many liters of water must be added to 18 liters of milk and water containing 10 % water to make it 40 % water ?
"by rule of alligation : 40 % - 10 % = 30 % 100 % - 40 % = 60 % quantity of pure water : quantity of the mixture = 1 : 2 there are 18 liters of mixture , so we need to add 9 liters of pure water . the answer is d ."
multiply(divide(18, 10), divide(40, 10))