in a mixture of 20 litres, the pure milk is 60%,what quantity of water should be added so that pure milk becomes 40%?​

4 litres

Step-by-step explanation:

First, we are going to find 60% of 20 litres.

20 × = 12 litres

∴ Pure milk 12 litres.

Now we find 40% of 20 litres.

20 × = 8 litres

To find the quantity of water to be added we subtract the 8 litres from the 12 litres.

12 - 8 = 4 litres

∴ 4 litres of water should be added so that pure milk becomes 40%

-2 is the right