Question

Two cubes of same side 6 cm are joined end to end. Then, the total surface area of the new cuboid is

• A. $546$ $c{m}^2$
• B. $500$ $c{m}^2$
• C. $360$ $c{m}^2$
• D. $400$ $c{m}^2$

Answer 1

The correct option is C $360$ $c{m}^2$

Let the side length of the cube be a.
Then the length, breadth and height of the resultant cuboid are 2a, a and a, respectively.

$\therefore \text{TSA of cuboid}=2(lb+bh+hl)$
=2[(2a)(a) + (a)(a) + (a)(2a)]
$=2(2a^2+a^2+2a^2)$
$=10a^2$
$=10\times (6{)}^2$ $(\because a=6cm)$
$=360$ $c{m}^2$
Hence, the correct answer is option (c).