Question

A closed wooden box 80 cm long, 65 cm wide and 45 cm high, is made of 2.5 cm-thick wood. Find the capacity of the box and its weight if $100c{m}^3$ of wood weighs 8 g.

Answer 1

Outer length =80 cm.

Outer width =65 cm.

Outer height =45 cm.

Total volume $=80\times 65\times 45c{m}^3$

$=234000c{m}^3$

Thickness of wood =2.5 cm.

$\therefore$ Inner length $=80-2\times 2.5=75cm.$

Inner width $=65-2\times 2.5=60$ cm.

Inner height $=45-2\times 2.5=40$ cm.

(i)\therefore Inner capacity (volume)

$=75\times 60\times 40c{m}^{3}3=180000c{m}^3$

Volume of wood $=234000-180000$

$=54000c{m}^3$

$\therefore$ Weight of wood $=\frac{54000\times 8}{100}g$

$=4320g=4.320kg$