Question

A mason constructs a wall of dimensions $270$ cm $\times$ $300$ cm $\times$ $350$ cm with the bricks each of size $22.5$ cm $\times$ $11.25$ cm $\times$ $8.75$ cm and it is assumed that $\frac{1}{8}$ space is covered by the mortar. Then the number of bricks used to construct the wall is

• A. $11100$
• B. $11200$
• C. $11000$
• D. $11300$

Answer 1

The correct option is B $11200$

Volume of wall$=\left(270\right)\left(300\right)\left(350\right)=28350000c{m}^3$

Volume of brick$=\left(22.5\right)\left(11.25\right)\left(8.75\right)=2214.84375c{m}^3$

$\frac{1}{8}$ space is covered by morter $=\frac{28350000}{8}=3543750$

Surface constructed$=28350000-3543750=24806250$

Number of bricks$=\frac{24806250}{2214.84375}=11200$