Start with a volume of a cuboid,
[tex]V=abc=3\cdot2\cdot3=18\mathrm{cm^3}[/tex]
The side of the cube we need equals to the LCM of the cubiod's sides,
[tex]\mathrm{LCM}(a,b,c)=\mathrm{LCM}(3,2,3)=6[/tex]
Now compute the volume of such cube,
[tex]V=\mathrm{LCM}(a,b,c)^3=6^3=216\mathrm{cm^3}[/tex]
Divide the volumes to get how many cubiods are in such cube,
[tex]\dfrac{V_{\mathrm{cube}}}{V_{\mathrm{cubiod}}}=\dfrac{216}{18}=\boxed{12}[/tex]
Hope this helps :)
