Question

A wall $5m$ long, $30cm$ wide and $4cm$ height is made of bricks, each measuring $(22cm\times 12.5cm\times 12.5cm)$. If $\frac{1}{12}$ of the total volume of the wall consists of motor, how many bricks are there in the wall?

Answer 1

Volume of wall$=L\times B\times H$

$=1500\times 30\times 4$

$=180000c{m}^3$

Volume of brick$=l\times b\times h$

$=22\times 12.5\times 12.5$

$=3437.5c{m}^3$

Volume consisting motor$=\frac{1}{12}$ of volume of wall

$=\frac{1}{12}\times 1800000$

$=15000c{m}^3$

$\therefore$ No. of bricks required $=\frac{Leftvolume}{Volumeofbrick}$

$=\frac{180000-15000}{3437.5}=48$.