Question

A wall 4 m long, 3 m high and 0.4 m thick is to be built. How many bricks 20 cm long, 12 cm broad and 10 cm thick will be required?

Answer 1

Length of wall = 4 m
Breadth of wall = 0.4 m
Height of wall = 3 m
Since, volume of a cuboid = length × breadth × height
⇒ Volume of wall = 4 m × 0.4 m × 3 m = 4.8 m³
Since, 1 cm = 0.01 m
Length of brick = 20 cm = 0.20 m
Breadth of brick = 12 cm = 0.12 m
Height of brick = 10 cm = 0.1 m
Volume of brick = 0.20 m × 0.12 m × 0.1 m = 0.0024 m³
The number of bricks required to build the wall$=\frac{\mathrm{volume}\mathrm{of}\mathrm{wall}}{\mathrm{volume}\mathrm{of}\mathrm{brick}}$
$$\begin{gathered} =\frac{4.8}{0.0024}=\frac{48\times 10000}{24\times 10} \\ =2000 \end{gathered}$$
Thus, 2000 bricks are required to build the wall.