"200 litres of milk contains 10% of water .How much more water should be added to it
so that water maybe 20% in mixture?"
This is a standard Algebra I problem.
Let x = the amount of water to be added.
Imagine two containers: One contains the 200 L of 10% solution and the other just water.
There is 20 L (200 • 10%) of water in the first container. After adding x L of water, we will have (200 + x) L of water, which will be 20% of the total amount.
Let's write an equation about the amount of water.
200(0.1) + x = (200 + x)(0.2)
Solve for x.