Question

What is the number of bricks, each measuring $25$ cm $\times$ $12.5$ cm $\times$ $7.5$ cm required to construct a wall $6$ m long, $5$ m high, and $0.5$ m thick, if mortar occupies $5\%$ of the volume of the wall?

• A. $5740$
• B. $6080$
• C. $3040$
• D. $8120$

Answer 1

The correct option is B $6080$

Number of bricks $=\frac{\text{95\% of volume of wall}}{\text{Volume of a brick}}$ $=\frac{0.95\times 600\times 500\times 50}{25\times 12.5\times 7.5}=6080$