Question

A wall 24m long ,5 m high and 0.25m thick is to be constructed using bricks measuring 25cm×12.5cm×7.5cm. Find the no. of bricks required,if 5% of the wall is occupied by cement and sand mixture.

Answer 1

volume of the wall = 24m×5m×0.25m
=2400cm×500cm×25cm
= 30,000,000cm^3
5% of wall is occupied by cement and sand mixture. therefore we need to construct 95% of wall using bricks. 95% of wall = 30,000,000×95÷100= 28,500,000
and the volume of bricks = 25×12.5×7.5=2343.75 cm^3
so, no of bricks required
$28500000 \div 2343.75 = 1260 \: pcs$