Let the edge of each smaller cube be xm. Then, volume of each smaller cube =(x3)m3. Volume of 8 smaller cubes =(8x3)m3. Volume of 8 smaller cubes = Volume of the original cube. ⇒8x3=72⇒x3=9⇒x=3√9m Thus, the edge of a smaller cube =3√9m. The edge of the original cube =(3√72)m=(2×3√9)m ∴ Required ratio =3√9:2×3√9=1:2