Question

Three cubes each of side $3.2$ cm are joined end to end. Find the total surface area of the resulting cuboid (in $c{m}^2$)

• A. $124.51$
• B. $136.15$
• C. $143.36$
• D. $148.27$

Answer 1

The correct option is C $143.36$

When three cubes of side $3.2$ cm are joined, the resulting shape is a cuboid of length $3.2\times 3=9.6$ cm; breadth $=3.2$ cm and height $=3.2$ cm
So, total surface area of a cuboid $=2(lb+bh+lh)$

$=2(9.6\times 3.2+3.2\times 3.2+9.6\times 3.2)$

$=143.36$ sq.cm