Question

Two cubes each of volume $27c{m}^3$ are joined end to end to form a solid. Find the surface area (cm${}^2$) of the resulting cuboid.

Answer 1

Volume of one cube, $v=27{cm}^3$

Therefore, side of a cube $s=v^{1/3}={27}^{1/3}=3cm$

Two cubes of the same volume joined together to form a cuboid.

Therefore, the length of cuboid, $L=2s=6cm$

Width of cuboid (B) = Height of cuboid (H) $=s=3cm$

Surface Area of cuboid,

$S.A=2(LB+BH+LH)=2(6\times 3+3\times 3+6\times 3)=2(18+9+18)=90{cm}^2$