Through a rectangular field of length 90 m and breadth 60 m , two roads are constructed which are parallel to the sides and cut each other at right angles through the centre of the fields. If the width of each road is 3 m .find the cost of constructing the roads at the rate of Rs. $110$ per $\mathrm{m}^2$.
It is given that the width of each road is 3 m and the length of rectangular park is 90 m and breadth is 60 m Now, We know that the area of a rectangle is =length $\times$ breadth
The area of the total park is
$\Rightarrow 90 \times 60=5400 \mathrm{~m}^2$
The area of road parallel to the width of the park (PQRS) is
$\Rightarrow 60 \times 3=180 \mathrm{~m}^2$
The area of road parallel to the length of the park (EFGH) is
$\Rightarrow 3 \times 90=270 \mathrm{~m}^2$
The common area of both the roads (KLMN) is
$\Rightarrow 3 \times 3=9 m^2$
$\text { Area of roads }=[(i i)+(i i i)-(i v)]$
$\Rightarrow 180+270-9=441 \mathrm{~m}^2$
Now, the cost of constructing the roads at the rate of Rs. $110$ per $\mathrm{m}^2$ is
$\Rightarrow 441 \times 110=48510$ Rs
Therefore, the cost of constructing the roads at the rate of Rs. $110$ per $\mathrm{m}^2$ is Rs. $48510$.