Question

A path 5m wide runs along inside a square park of side 100m .find the area of the path.also find the cost of cementing it at the rate of rs250 per 10m2

Answer 1

see the attached figure :- 
given , 
length of the big square = 100 m
length of the small square = 5 m
Side of the smaller square = Side of the bigger square - 2(width of the path)
                                           = 100 - 2(5)
                                           = 90 m
Area of the path = (100)² - (90)² = 10000 - 8100 = 1900 sq m

Cost of cementing at the rate of Rs 250 per 10 m² = 250 x 190 = Rs 47500
           i hope it helps..........................^_^

Answer 2

Area of path = Area of bigger square - Area of smaller square
Side of the smaller square = Side of the bigger square - 2(width of the path)
                                           = 100 - 2(5)
                                           = 90 m
Area of the path = (100)² - (90)² = 10000 - 8100 = 1900 sq m

Cost of cementing at the rate of Rs 250 per 10 m² = 250 x 190 = Rs 47500