Question

How many bricks of length 25 cm, breadth 15 cm and height 10 cm are required to build a wall of length 6 m, height 2.5 m and breadth 0.5 m?

Answer 1

Given: 

For the cuboidal shape brick: 

length (l₁) = 25 cm, 

breadth (b₁) = 15 cm,

height (h₁) = 10 cm

For the cuboidal shape wall:

length (l₂) = 6 m, 

height (h₂) = 2.5 m, 

breadth (b₂) = 0.5 m

To find: Number of bricks required.

When all the bricks are arranged to build a wall, the volume of all the bricks is equal to volume of wall.

\(\therefore\) Number of bricks = \(\cfrac{volume \,of \,the\,wall}{volume\,of\,a\,brick}\)

i. Volume of a brick = l₁ x b₁ x h₁ 

= 25 x 15 x 10 cc

ii. l₂ = 6m = 6 x 100 …[∵ 1m = 100cm] 

= 600 cm

h₂ = 2.5 m = 2.5 x 100 = 250 cm

b₂ = 0.5 m = 0.5 x 100 = 50 cm

Volume of the wall = l₂ x b₂ x h₂

= 600 x 50 x 250 cc

iii.  Number of bricks = \(\cfrac{volume \,of \,the\,wall}{volume\,of\,a\,brick}\)

= 40 x 2 x 25 

= 2000 bricks 

∴ 2000 bricks are required to build the wall.