Question

If the thickness of the wall of the box is $1$ cm on all sides, find the amount of wood required to build this box.

• A. $288$ cm${}^3$
• B. $480$ cm${}^3$
• C. $192$ cm${}^3$

Answer 1

The correct option is A $288$ cm${}^3$

The amount of wood required to build this box is the volume of the wooden walls.
The box has a $1$ cm thick wooded wall, so the external dimension is different than the internal dimension.

Externally:
Length $l=10$ cm
Breadth $b=6$ cm
Height $h=8$ cm
Volume $=l\times b\times h=10\times 6\times 8=480$ cm${}^3$

Internally:
Length $l=10-2=8$ cm
Breadth $b=6-2=4$ cm
Height $h=8-2=6$ cm
Volume $=l\times b\times h=8\times 4\times 6=192$ cm${}^3$

$\therefore$ Volume of the wood $=480-192=288$ cm${}^3$

Option (a.) is correct.