Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: · Marks: · Difficulty:
The number of bricks, each measuring 25 cm × 12.5 cm × 7.5 cm, required to construct a wall 6 m long, 5 m high and 0.5 m thick, while the mortar occupies 5\% of the volume of the wall, is
(a)3040
(b)5740
(c)6080
(d)8120
Answer
Answer (as printed): C
Explanation
Volume of the bricks = 95\% of volume of wall $$=\left(\frac{95}{100} \times 600 \times 500 \times 50\right) \mathrm{cm}^{3} .$$ Volume of 1 brick $=(25 \times 12.5 \times 7.5) \mathrm{cm}^{3}$. $$\text { ∴ Number of bricks }=\left(\frac{95}{100} \times \frac{600 \times 500 \times 50}{25 \times 12.5 \times 7.5}\right)=6080 .$$
Explanation as extracted from the printed page; notation may be imperfect.