Question

The surface area of a cube is $1536{\text{cm}}^2$.
Find:
(i) the length if its edge
(ii) its volume
(iii) the volume of its material whose thickness is $5\text{mm}$.

Answer 1

Let side of cube $=a\text{cm}$

Surface area of cube $=6a^2$

$\Rightarrow 6a^2=1536$

$\Rightarrow a^2=256$

$\Rightarrow a=16\text{cm}$

Volume $=a^3=16\times 16\times 16=4096{\text{cm}}^3$

Volume of material $=$ Surface area $\times$ thickness

$=1536\times \frac{5}{10}$ [to convert thickness into cm]

$=768c{m}^3$