Question

The radius of a circular garden is 100 m. There is a road 10 m wide, running all around it. Find the area of the road and the cost of levelling it at Rs 20 per m². [Use π = 3.14.] 

Answer 1

Area of the road = Area of outer circle − Area of inner circle

= πR² - πr²

= π [(110)² - (100)²]

= 3.14 × 2100

= 6594 m²

Cost of levelling the road = Area of the road ⨯ Rate
= 6594 ⨯ 20
= Rs 131880