Question

A wall 4 metre long, 3 metre high and 13 cm thick is made up of bricks each measuring 20 cm $\times$ 12 cm $\times$ 6.5 cm. The number of bricks required is

• A. 500
• B. 1000
• C. 1500
• D. 2000

Answer 1

The correct option is B 1000

Since the wall with all its bricks makes up the space occupied by it, we need to find the volume of the wall, which is nothing but a cuboid.

Length=4 meter=400 cm

Height=3 meter=300 cm

Thickness=13 cm

$\therefore$Volume of the wall=$length\times height\times thickness$

$\Rightarrow 400\times 300\times 13=1560000c{m}^3$

Now, each brick is a cuboid with length = 20 cm, breadth = 12 cm and height = 6.5 cm

$\therefore$Volume of each Bricks=$Length\times breath\times height$

$\Rightarrow 20\times 12\times 6.5=1560cm$

$\therefore$No. of bricks required=$\frac{volumeofwall}{Volumeofeachbricks}=\frac{1560000}{1560}=1000$