Question

Two identical cubes of side 4 cm are placed one above the other, forming a cuboid. Find the total surface area of the cuboid thus formed.

• A. $96{\text{cm}}^2$
• B. $100{\text{cm}}^2$
• C. $160{\text{cm}}^2$
• D. $180{\text{cm}}^2$

Answer 1

The correct option is C

$160{\text{cm}}^2$

The cuboid formed after placing two identical cubes one above the other has following dimensions:

$\text{Length,}l=4\text{cm}$
$\text{Breadth,}b=4\text{cm}$
$\text{Height,}h=4+4=8\text{cm}$
We know, total surface area (TSA) of a cuboid of dimensions $l\times b\times h$ is given by '$2(lb+bh+hl)$'.
So, total surface of the cuboid formed
$=2(4\times 4+4\times 8+8\times 4)$
$=2\times (16+32+32)$
$=2\times 80=160{\text{cm}}^2$