Ratio of water and milk in a container is 2 : 3. If 40 liter mixture removed from the container and same quantity of milk is added to it then the ratio of water to milk becomes 1 : 4. Find the initial quantity of mixture ?

From the given data,

let the initial quantity of the mixture = 5x

Then,

$\frac{2x - 16}{3x - 24 + 40} = \frac{1}{4}8x - 64 = 3x + 165x = 80x = 16 \mathrm{lit}$

Then the initial quantity of the mixture = 5x = 5 x 16 = 80 lit.