Question

A worker needs to lay a 20 cm long and 9 cm wide path, how many pieces of steel slab each 10 cm long and 3 cm wide are required?

Answer 1

Step 1: For each slab, length = 10 cm, width = 3 cm

The area of a slab = length × breadth
$=10cm\times 3cm$
$=30c{m}^2$

Step 2: For the path, length = 20 cm, width = 9 cm

The area of the path = length × breadth
$=20cm\times 9cm$
$=180c{m}^2$

Step 3:
As the area of the path is equal to product of the area of each slab and required number of slabs.
$\therefore \text{Required number of slabs}=\frac{\text{Area of the path}}{\text{Area of each slab}}$
$=\frac{180c{m}^2}{30c{m}^2}$
$=\frac{30\times 6}{30}$
$=6$