Question

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

• A. $100$
• B. $200$
• C. $150$
• D. $120$

Answer 1

The correct option is A $100$

For a brick
length $l=22.5cm$; breadth $b=10cm$; height $h=7.5cm$

$\therefore$ Total surface area of a brick $=\frac{2(lb+bh+hl)}{2(22.5\times 10+10\times 7.5+7.5\times 22.5)}$

$=2(225+75+168.75)$

$=2\left(468.75\right)=937.5{cm}^2=0.09375m^2$

$\therefore$ Number of bricks that can be painted out

$=\frac{9.375}{.09375}=100$

Hence, $100$ bricks can be pained out of the given container.