Find the number of bricks, each measuring 25 cm, 12.5 cm and 7.5 cm required to construct a wall 6 m long , 5 m high and 50 cm thick, while the cement and sand mixture occupies `1/20 th` of the volume of the wall.

Explanation

Given
wall dimensions is `6 `m long, `5` m high, `0.5` m thick.
volume of wall `= 6 xx 5 xx 0.5 = 15m^3`
Given, cement and sand mixture occupies `1/20` of the volume of the wall.
Therefore, volume of the wall occupied by the bricks ` = (1-1/20 )`
volume of wall = `19/20`
volume of the wall = `19/20 × 15 = 14.25m^3`
Now, volume of each brick `= 25/100 m × 125/1000 m × 75/1000 m`
So, the number of bricks required = volume of wall /volume of each brick
` =frac{ 14.25m^3 }{25/100m × 125/1000m × 75/1000m} = 6080`
Hence, `6080` bricks of given dimensions are required to construct the wall.