Typically cylinder was graduated in mL
The volume of the metal is indicated by how much the water level rises in the cylinder.
Volume of metal = New level - Initial level = 70 - 50 =20 mL
Density = Mass / Volume
= 140 g / 20 mL
= 7 g/mL
Density of the metal = 7 g/mL
Note that 1 mL = 1 cm³. Therefore 7g/mL = 7 g/cm³.
Density = 7g/mL or 7 g/cm³.
I hope this helps.
