Question

51. 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 * 20 per m. [Use = 3.14.]
CBSE 2017​

Answer 1

Step-by-step explanation:

area = Πr^2

area of gardern = 3.14 ×100×100

= 31400

area of garden with the area of road = 3.14×110×110

= 37994

so area of road = 37994-31400

6594

so leveling it at 20 per square meter will cost 6594×20 = 13188

Answer 2

Answer:

Area of Road = 6,594 Square Meter

Cost for Leveling the road = Rs 1,31,880.00

Step-by-step explanation:

Radius of Circular Garden, r = 100M

Width of Road = 10 M

Radius of Garden including road, R = 100 + 10 = 110M

ie Outer Radius, R = 110M

Area of Road = Outer Area - Inner Area

Area of a circle is $\pi$$r^{2}$, where r is the radius of the circle

ie Area of road = $\pi R^{2}$ - $\pi r^{2}$

= $\pi (110^{2} )$ - $\pi (100^{2} )$

Let $\pi$ = 3.14

= 3.14 ($110^{2}$ - $100^{2}$)

=3.14 (12100-10000)

=3.14 x 2100

=6,594 Sq. Meter

Cost of leveling the road = Rs 20 Per Square Meter

Therefore Total Cost = Rs 20 x 6594

= Rs 1,31,880.00