Answer:
The correct answer is 1.33
.
Step-by-step explanation:
The mass of the rock is 8.20 kg. To know its density we must first know its volume. By immersing it in water, we can calculate the volume of water dislodged through the density of the water and the mass. The apparent mass of the object is 6.18 kg. If we divide this value by the density of the water we will obtain the volume of the rock.
V =

V = 6.18 L
Now we can calculate the density (δ) of the object by knowing its mass and volume.
δ =

δ = 1.33 Kg / L
Have a nice day!