Question:
Tick (✓) the correct answer:
An iron beam is 9 m long, 40 cm wide and 20 cm high. If 1 cubic metre of iron weighs 50 kg, what is the weight of the beam?
(a) 56 kg
(b) 48 kg
(c) 36 kg
(d) 27 kg
Solution:
(c) $36 \mathrm{~kg}$
Volume of the iron beam $=9 \times 0.4 \times 0.2=0.72 \mathrm{~m}^{3}$
$\therefore$ Weight $=0.72 \times 50=36 \mathrm{~kg}$