A container contains 50 litres of milk. From that 8 litres of milk was taken out and replaced by water. This process was repeated further two times. How much milk is now contained by the container ?

Given that container has 50 litres of milk.

 After replacing 8 litres of milk with water for three times, milk contained in the container is:

  $\Rightarrow 501-\frac{8}{50}3$

$\Rightarrow 50\times \frac{42}{50}\times \frac{42}{50}\times \frac{42}{50}$  = 29.63 litres.