A mixture contains milk and water in the ratio of 7 : 8. If 10 litres water and 5 litres milk is added in the mixture then the ratio of water and milk becomes 3 : 2. Find the initial quantity in the mixture?

Two equal glasses are filled with alcohol and water respectively. First glass is filled with (2/5) of alcohol and second glass is filled with (1/4) of alcohol. Then, the glasses are filled up with water and the resultant mixture is put into a big Jug. Find the ratio of alcohol and water in the jug.

Milkman has a container filled with a mixture of milk and water which are in the ratio of 7 : 3. How many parts of the mixture needs to be removed and replaced from the water to obtain milk and water in ratio of 1 : 1?