In 80 litres mixture of milk and water the ratio of amount

In 80 litres mixture of milk and water the ratio of amount of milk to that of amount of water is 7 : 3. In order to make this ratio 2 : 1, how many litres of water should be added ?

Quantity of milk

=	7	× 80 = 56 litres
	10

Quantity of water

=	3	× 80 = 24 litres
	10

Let x litre water be added

Then,	56	=	2
	24 + x		1

⇒ 24 + x = 28
x = 4 litres