A mason constructs a wall of dimensions $(270 \mathrm{~cm} \times 300 \mathrm{~cm} \times 350 \mathrm{~cm})$ with bricks, each of size $(22.5 \mathrm{~cm} \times 11.25 \mathrm{~cm} \times 8.75 \mathrm{~cm})$ and it is assumed that $\frac{1}{8}$
space is covered by the mortar. Number of bricks used to construct the wall is
(a) 11000
(b) 11100
(c) 11200
(d) 11300
(c) 11200
Volume of wall $=270 \times 300 \times 350 \mathrm{~cm}^{3}$
$\frac{1}{8}$ th of the wall is covered with mortar.
So,
Volume of the wall filled with bricks $=\left(\frac{7}{8} \times 270 \times 300 \times 350\right) \mathrm{cm}^{3}$
Volume of each brick $=\left(\frac{225}{10} \times \frac{1125}{100} \times \frac{875}{100}\right) \mathrm{cm}^{3}$
$=\left(\frac{9 \times 22 \times 32}{32}\right) \mathrm{cm}^{3}$
Number of bricks used to construct the wall $=\frac{\text { Volume of the wall composed of bricks }}{\text { Volulme of each brick }}$
$=\frac{7 \times 270 \times 300 \times 350 \times 32}{8 \times 9 \times 225 \times 35}$
$=11200$
Hence, the number of bricks used to construct the wall is 11200.