Question

External dimensions of a wooden cuboid are $30cm\times 25cm\times 20cm$. If the thickness of wood is $2cm$ all round find the volume of the wood contained in cuboid formed.

Answer 1

External volume $=30\times 25\times 20=15000c{m}^3$

Internal dimensions $=(30-4)cm\times (25-4)cm\times (20-4)cm$

$=26cm\times 21cm\times 16cm$

Internal volume $=26cm\times 21cm\times 16cm$

$=8736c{m}^3$

Volume of wood = external volume - internal volume

$=(15000-8735)c{m}^3$

$=6265c{m}^3$