Question

A wooden box (including the lid) has external dimensions 40 cm by 34 cm by 30 cm. If the wood is 1 cm thick, how many cm³ of wood is used in it?

Answer 1

External dimensions of wooden box are 40 cm × 34 cm × 30 cm.

Since, the wood is 1 cm thick, it means the internal dimensions will be (40 – 2) cm × (34 – 2) cm × (30 – 2) cm = 38 cm × 32 cm × 28 cm

∴ Wood used for the box = Volume of the wooden box with external dimensions – Volume of the wooden box with internal dimensions

= 40 × 34 × 30 – 38 × 32 × 28

= 40800 – 34048

= 6752 cm³