Question

How many bricks of $20$ cm by $10$ cm will be needed to make the floor of a room $25$ m long and 16 m wide?

Answer 1

Area of the room $=25m\times 16m$
$=400m^2$
Area of the brick $=20cm\times 10cm$
$=\frac{1}{5}m\times \frac{1}{10}m$
$=\frac{1}{50}{m}^2$
$\therefore$ Number of bricks required $=(400÷\frac{1}{50})$
$=20,000$