A container of certain quantity was full of milk. 8 liters liquid drawn off and replaced by water and this process is repeated two times therefore ratio of water and milk becomes 56 : 25. Find original quantity of milk in the container?

18 liters

let x be the quanity of the mixture

\(\frac{milk\; left}{water\; added}\) = \(\frac{25}{56}\)

It means, \(\frac{milk\; left}{initial\; milk\; quantity}\) = \(\frac{25}{81}\)

\(\frac{25}{81}\) = \( {(1 - \frac{8}{x}) }^{2 } \)

\(\frac{5}{9}\) = (1 - \(\frac{8}{x}\)) 

x = 18 litres