Find the number of bricks, each measuring `25 cm xx 12. 5 c m xx 7. 5 c m` required to construct a wall `6 m ` long, `5 m` high and `0. 5 m` thick, while the cement and sand mixture occupies `1/(20)` of the volume of the wall.

Explanation

volume of wall`=6xx5xx0.5m^3=15m^3`

volume occupied by bricks`=(19/20)xx15m^3`

`=(57/4)m^3`

so no of bricks`= [(57/4)cm^3]/(0.25xx0.125xx0.075)xx100xx100xx100
``=6.08xx10^9`