Given:

- Initial milk quantity = 40 litres
- Milk and water are equally replaced in each iteration
- After 3 iterations, milk quantity = 20.48 litres

To find:

- The amount of solution (in litres) removed in each iteration

Solution:

Let's work backwards from the final quantity of milk to find the amount of milk and water in the container after each iteration.

After the third iteration:

- Milk quantity = 20.48 litres
- Volume of solution = 40 litres (initial volume)

Let's assume that x litres of solution (containing milk and water) is replaced in each iteration.

After the second iteration:

- Milk quantity = (40 - x) litres (since x litres of solution containing milk and water is removed and replaced with an equal amount of water)
- Volume of solution = 40 litres (since the same amount of solution is replaced in each iteration)

Now, let's use the above information to find the amount of milk in the container after the first iteration.

After the first iteration:

- Milk quantity = (40 - x) litres (since x litres of solution containing milk and water is removed and replaced with an equal amount of water)
- Volume of solution = 40 litres (since the same amount of solution is replaced in each iteration)

Since the milk and water are equally replaced in each iteration, the ratio of milk to solution remains constant. Using this fact, we can set up the following equation:

(milk quantity after 1st iteration) / (total volume after 1st iteration) = (milk quantity after 2nd iteration) / (total volume after 2nd iteration)

Substituting the values we found earlier:

(40 - x) / 40 = (40 - x) / (40 - x + x)

Simplifying,

(40 - x) / 40 = (40 - x) / 40

This equation is true for any value of x, which means that the amount of solution removed in each iteration can be any value. However, we are given that the correct answer is 8.

To verify this, let's use the information we found earlier to solve for x:

After the second iteration:

- Milk quantity = (40 - x) litres
- Volume of solution = 40 litres

Using the same equation as before:

(milk quantity after 2nd iteration) / (total volume after 2nd iteration) = (milk quantity after 3rd iteration) / (total volume after 3rd iteration)

Substituting the values we found earlier:

(40 - x) / 40 = 20.48 / (40 - x + x)

Simplifying,

(40 - x) / 40 = 20.48 / 40

Solving for x,

40 - x = 20.48

x = 19.52

Therefore, the amount of solution (containing milk and water) removed in each iteration is:

= 19.52 / 3

= 6.51 (approx)

This is not the correct answer. However, we made an assumption earlier that the ratio of milk to solution remains constant in each iteration. This is only true if the volume of solution removed and replaced is the same in

Let amout of milk getting reduced is by k then,
40 * k * k * k = 20.48
from above k = 4/5
now if 4/5 is quantity decreased by then water added is by 1-4/5 = 1/5
now let x litres is removed each time then x/40 = 1/5
therefore x = 8.