80 litres of a mixture contains milk and water in the ratio of 27 ∶ 5. How much more water is to be added to get a mixture containing milk and water in the ratio of 3 ∶ 1?

Given:

80 liters of a mixture contain milk and water in the ratio of 27 ∶ 5.

Calculation:

Milk = \(\dfrac{27}{32}\) × 80 = 67.5 L

Water = 80 - 67.5 = 12.5 L

Let, m = water to be added to get 3 : 1

⇒ \(\dfrac{67.5}{12.5 + m}\) = 3

⇒ 67.5 = 37.5 + 3m

⇒ m = 10

∴ The quantity of water to be added to get 3 : 1, is 10 litres.