Are the levels of water and milk same ?

Milk is

What is the effective density of the mixture of water and milk when they are taken with same volumes ?

What is the effective density of the mixture of water and milk when i. they are taken with same masses ?

During the summer the level of water in a pond decreases by inches every week due to evaporation. What is the chanage in the level of the water over a period of 6 weeks?