Question

The paint in a certain container is sufficient to paint an area equal to 9.375 m^2. How many bricks of dimensions 22.5 cm × 10 cm × 7.5 cm can be painted out of this container?

Answer 1

Let l = 22.5 cm, b = 10 cm and h = 7.5 cm
Surface area of each brick
= 2(lb + bh + lh)
= 2(22.5 × 10 + 10 ×7.5 + 7.5 × 22.5 cm²
= 2 (225 + 75 + 168.75) cm²
= 2(468.75) cm² = 937.5 cm²

Area that can be painted using the paint of container = 9.375 m² = 9.375 × 100 × 100 cm²

Number of bricks that can be painted
$= \frac{Total \: area \: that \: can \: be \: painted}{ Surface \: area \: of \: each \: brick }$
$= \frac{9.375 \times 100 \times 100 \: cm {}^{2} }{937.5 \: cm {}^{2} } = 100$

Hence, 100 bricks can be painted out of the paint given in the container.