The milk and water in a mixture are in the ratio of 7 : 5. When 15 litres of water are added to it, the ratio of milk and water in the new mixture becomes 7 : 8. The total quantity of water in the new mixture is:

40 liters

The ratio of Milk and Water = 7 : 5

When 15 litres of water added, the ratio becomes 7 : 8.

The initial ratio of milk and water = 7x : 5x

When 15 litres of water added

⇒ \(\frac{(7x)}{( 5x + 15)}\)  = 7 : 8

⇒ 56x = 35x + 105

⇒ 21x = 105

⇒ x = 5

Quantity of water in new mixture

⇒ 8 × 5 = 40

∴ The quantity of water in new mixture is 40 litres.