The density of a substance is its mass per unit volume.
[tex]\rho=\frac{m}{V}[/tex]where,
ρ (rho) =density
m=mass
V=volume
in this example
m = 6 grams
V = 2*6*3 = 12*3 = 36 in^3
therefore,
[tex]\rho=\frac{6}{36}=\frac{1}{6}[/tex]This is the same as:
[tex]\rho=\frac{1}{6}=0.17[/tex]