A 80 m by 64 m rectangular lawn has two roads, each 5 m wide, running through its middle, one parallel to its length and the other parallel to its breadth. Find the cost of gravelling the roads at RS. 40 per m2.
Given:
Length = 80 m
Breadth = 64 m
Width of road = 5 m
Cost = Rs 40 per m2
Area of horizontal road = 5 m × 80 m
= 400 m2
Area of vertical road = 5 m × 64 m
= 320 m2
Area of common part to both roads = 5 m × 5 m
= 25 m2
Now,
Area of roads to be gravelled = Area of horizontal road + Area of vertical road - Area of common part to both roads
= 400 m2 + 320 m2 - 25 m2
= 695 m2
Cost of gravelling = 695 m2 × Rs 40 per m2
= Rs 27800