Question

The cost of decorating the circumference of a circular lawn of a house at the rate of ₹ 55 per metre is ₹ 16940. What is the radius of the lawn?

Answer 1

Cost of decorating the circumference = ₹ 16,940

Cost of decorating per meter = ₹ 55

∴ Length of the circumference = ${\displaystyle \frac{16940}{55} \text{m}}$ = 308 m

Circumference of the circular lawn = 308 m

2 × πr = 308 m

${\displaystyle 2\times \frac{22}{7}\times \text{r}}$ = 308 m

r = ${\displaystyle \frac{308\times 7}{2\times 22}}$

r = 49 m

Radius of the lawn = 49 m