Question

The area of a circular playground is $22176$ $m^2.$ The cost of fencing this ground at the rate of $Rs50$ per metre is

• A. $Rs52800$
• B. $Rs26400$
• C. $Rs13200$
• D. $Rs10560$

Answer 1

Answer: (B)

$Rs26400$

Given:

The area of a circular playground $=A=22176m^2$.

To find out:

The cost of fencing the ground at the rate of $Rs50/m$.

Solution:

The radius of the ground $=r=\sqrt{\frac{A}{\pi }}=\sqrt{\frac{22176}{22}\times 7}m=84m$.

$\therefore$ The circumference $=C=2\pi r=2\times \frac{22}{7}\times 84m=528m$.

Now, the length of the fence $=$ The length of the circumference.

$\therefore$ The cost of fencing the ground at the rate of $Rs50/m$

$=Rs528\times 50=Rs26400$