Answer:
Explanation: Take the apparatus fill it with water which is enough to sink the rock, next write down the reading of the apparatus with only the water. next drop the rock in the water and write down the reading with the water and the rock. next calculate change in volume ( here volume is the reading in the apparatus). next find the weight of the rock.
Then put the values into this equation
Density = mass/volume
if you took all the units in SI units then the unit of density is Kg/m^3