The mathematical and proportional relationship between mL and [tex] cm ^ 3 [/tex] said us that [tex] 1cm ^ 3 [/tex] is equivalent to 1mL.
If the density is considered as the amount of mass per unit volume we will have to
[tex]\rho = \frac{m}{V}[/tex]
here,
m = mass
V = Volume
Replacing we have that
[tex]\rho = \frac{40g}{23cm^3}[/tex]
[tex]\rho = 1.739g/cm^3[/tex]
As [tex]1mL = 1cm^3[/tex] we have that the density in g/mL is,
[tex]\rho = 1.739g/mL[/tex]