Question

Find the length of a cuboid whose breadth and height are 4 cm and 6 cm respectively and total surface area is 408 $c{m}^2$ is.

• A. 8 cm
• B. 18 cm
• C. 12 cm
• D. 16 cm

Answer 1

The correct option is B 18 cm

Total surface area of a cuboid is given by
2(lb + lh + bh)
where l, b and h represents the length, breadth and height repectively.

Since area is equal to 408 $c{m}^2$
2(lb + bh + lh ) = 408
lb + bh + lh = 204
$4l+24+6l=204$
$10l=204-24=180$
$l=18cm$

Therefore, length of the cuboid = 18 cm