Answer:
12.0 g/mL 
Step-by-step explanation:
From the question given above, the following data were obtained:
Mass of Rock = 360 g
Volume of water = 150 mL 
Volume of water + Rock = 180 mL 
Density of Rock =? 
Next, we shall determine the volume of the rock. This can be obtained as follow:
Volume of water = 150 mL 
Volume of water + Rock = 180 mL 
Volume of Rock =? 
Volume of Rock = (Volume of water + Rock) – (Volume of water)
Volume of Rock = 180 – 150
Volume of Rock = 30 mL 
Finally, we shall determine the density of the rock as illustrated below:
Mass of Rock = 360 g
Volume of Rock = 30 mL
Density of Rock =? 
Density = mass /volume 
Density of Rock = 360 / 30
Density of Rock = 12.0 g/mL 
Thus, the density of the rock is 12.0 g/mL