Question

The circumference of the playground is 528 m. Find the total expenditure of repairs of the ground at the rate of Rs.1.50 per square meter.

Answer 1

Hint: In order to solve this problem obtain the radius of the playground and multiply the cost with the area of the playground.

Complete step-by-step answer:
The circumference of the playground is 528m
As playground is circular and circumference of a circle is = $2\pi r\,\,\,\,\,\,\,\,\,\,\,\,\,\,\pi = \dfrac{{22}}{7}$
So, we can do $2\pi r$=528
$
  r = \dfrac{{528 \times {\text{7}}}}{{22 \times {\text{2}}}} \\
  r = 84m \\
$
So the radius of the playground is 84 meters.
Area of the playground is $\pi {r^2} = \dfrac{{22}}{7} \times {(84)^2} = 22176{m^2}$
It is also given that the cost of repairing the playground per square meter is 1.50.
So the total cost of repairing the playground is 1.50 x 22176 = 33264.
Hence the total expenditure is 33264.

Note: Whenever you face such types of problems in which a circular playground or item is given then the one thing you need to know is radius, then you can calculate its area and circumference as well. Here the circumference is given and we find the radius with the help of it then we have found the area to get the total cost of the playground.