Ans 2:
Class : Class 9
D is the correct answer.
At first milk is 40 L and water is 20 L
To set new proportion of 1:2, we have to add 60 L of water in milk.
Ans 3:
Class : Class 6
If ‘x’ is the common multiple, then the quantity of milk = 2x and quantity of water = xSo, 2x x = 60 litres3x = 60Or x = 60⁄3 = 20So, quantity of milk = 2x = 40 litres and quantity of water = x = 20 litresLet ‘y’ be the quantity of water to be added. So, quantity of water = (20 y)Then, 40 : (20 y) = 1 : 22 x 40 = 1(20 y)80 = 20 y20 y = 80So, y = 80 - 20 = 60Answer-(D) 60 litres