Q8 of 35 Page 311

At the centre of rectangular field of Pioneer atheletic club there is a circular Pool of which length of radius is 14 meter. The length and breadth of rectangular field are 60 meter and 42 meter respectively. Let us see by calculating how much cost it will take for planting grass of remaining place of rectangular field except pool at the rate of Rs. 75 per square meter.

Given, the field is rectangular in shape with length (l) = 60m and breadth (b) = 42m


In the center lies a circular pool with radius (r) = 14m


Since grass is planted within the field we will calculate area of the rectangular field


Area of rectangular field = l × b = 60 × 42 where l and b are length and breadth of rectangular field, respectively.


= 2520 m2


Area of circular pool = πr2 where r is the radius of circular pool


=


= 616 m2


The grass will be planted in the area = Area of rectangular field - Area of circular pool


= 2520 – 616 = 1904 m2


Cost of planting grass per meter is Rs75/ m2 = area of field × rate of planting per sq. meter


= 1904 × 75 = Rs 1,42, 800


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