Question 119959
First, express the volume in the same units (cm3 or m3)
I will convert the meters to centimeters
(.1 m)(100 cm/m) = 10 cm
and
(50m)(100 cm/m) = 5000 cm
Call the volume of the block {{{V}}}
{{{V = 25*10*5000}}} cm3
{{{V = 1.25*10^6}}}cm3
Call the density {{{D}}}
The definition of density is D = mass/volume
{{{D = 750 / (1.25*10^6)}}} kg/cm3
{{{D = (750*10^(-6)) / 1.25}}} kg/cm3
{{{D = 600*10^(-6)}}} kg/cm3 
{{{D = 6*10^2 *10^(-6)}}}kg/cm3
It might be more convienent to express this as grams/cm3
{{{D = 6*10^2 *10^(-6)}}}kg/cm3 x {{{1000}}}g/kg
{{{D = 6*10^5 * 10^(-6)}}} g/cm3
{{{D = .6}}}g/cm3 answer