Ametal sphere has a mass of 39.0g and a volume of 10.0cm is the sphere made of pure aluminum

Note that the density of pure aluminum is  2.7 g/cm³ (from tables).

Given:
m = 39.0 g, the mass of the metal
V = 10.0 cm³, the density of the metal

By definition, the density of the metal is
density = mass/volume
             = (39.0 g)/(10.0 cm³)
             = 3.9 g/cm³

The calculated density is not equal to 2.7 g/cm³, therefore the metal sphere is not made of pure aluminum.

Is there a picture or answer choices?

Ijust took the quiz. their is no coefficient needed. : )