According to Archimedes' principle, when an object displaces a liquid in a container, the volume displaced is numerically equal to the volume of the object. So, we solve for the displaced volume, then use the density to determine the mass of the aluminum cylinder.
Volume displaced = Volume of aluminum cylinder = 24.7 mL - 19.2 mL = 5.5 mL
The density is in terms of g/cm³. Note that 1 cm³ is just equal to 1 mL. Therefore,
Mass = 2.70 g/mL * 5.5 mL
Mass = 14.85 g
