Question

Mark (✓) against the correct answer in each of the following:
How many bricks will be required to construct a wall 13.5 m long, 6 m high and 22.5 cm thick if each brick measures (27 cm × 12.5 cm × 9 cm)?
(a) 6000
(b) 7500
(c) 5000
(d) 3750

Answer 1

(a) 6000

$$\begin{gathered} \text{L}\mathrm{ength}\mathrm{of}\text{the}\mathrm{wall}=13.5\mathrm{m}=1350\mathrm{cm} \\ \text{H}\mathrm{eight}\mathrm{of}\mathrm{wall}=6\mathrm{m}=600\mathrm{cm} \\ \text{B}\mathrm{readth}\mathrm{of}\mathrm{wall}=22.5\mathrm{cm} \\ \mathrm{Volume}\mathrm{of}\mathrm{wall}=\mathrm{Length}\times \mathrm{Breadth}\times \mathrm{Height} \\ =1350\times 22.5\times 600 \\ =18225000\mathrm{c}{\mathrm{m}}^3 \\ \mathrm{Volume}\mathrm{of}\text{a}\mathrm{brick}=\mathrm{Length}\times \mathrm{Breadth}\times \mathrm{Height} \\ =27\times 12.5\times 9 \\ =3037.5{\mathrm{cm}}^3 \\ \mathrm{Number}\mathrm{of}\mathrm{bricks}=\frac{\mathrm{Volume}\mathrm{of}\mathrm{wall}}{\mathrm{Volume}\mathrm{of}\text{a}\mathrm{brick}}=\frac{18225000}{3037.5}=6000 \end{gathered}$$