Question

How many cubic centimetres of iron is required to construct an open box whose external dimensions are $36$ cm, $25$ cm and $16.5$ cm provided the thickness of the iron is $1.5$ cm.

Answer 1

External volume $=\left(36\right)\left(25\right)\left(16.5\right)=14850c{m}^3$
Thickness of iron $=1.5$ cm
internal length $=36-1.5\left(2\right)=33$
internal breadth $=25-1.5\left(2\right)=22$
internal height $=16.5-1.5=15$
internal volume $=\left(33\right)\left(22\right)\left(15\right)=10890$

Volume of box $14850-10890=3960c{m}^3$