Arock weighing 30.0g is placed in a graduated cylinder displacing the volume from 22.3 ml to 27.6ml. what is density of the rock in grams/cubic centimeters?

Density=mass / volume

Data:
mass=30.0 g
volume=volume with rock - volume without rock=27.6 ml - 22.3 ml=5.3 ml

1 ml=cm³  ⇒ 5.3 ml=5.3 cm³

Therefore:

Density=30.0 g / 5.3 cm³=5.66 g/cm³

density = 5.66 g/cm³