Question

What is the cost of fencing a circular plate of radius 7.7 m with three rounds of wire, if the wire costs Rs 50 per m?

Answer 1

Radius of the circular plate is 7.7 m.
Circumference of a circle = 2πr
Circumference = 2 × π × 7.7 m
= $\frac{22}{7}$ ×15.4 $\left(\mathrm{Taking}\mathrm{\pi }=\frac{22}{7}\right)$
= 48.4 m
∴ Circumference of the plate is 48.4 m
Cost of fencing the plate is Rs 50 per m.
Number of rounds required in fencing = 3
Total cost = (Number of rounds required in fencing ) × (Cost of fencing the plate) × (circumference)
= Rs (50 × 3 × 48.4) = Rs. 7,260

Therefore, total cost of fencing the circular plate = Rs. 7,260.