Question

3. Find the cost of developing 7m wide road at outer side of a circular garden having 12m radius at a rate of
Rs 50 per sq. meter.
​

Answer 1

radius of inner circle =r=12m

radius of outer circle =R=12+7=19m

area of road =area of outer circle - area of inner circle

=πR^2-πr^2

=π(R^2-r^2)

22/7(19*19-12*12)

22/7(361-144)

22/7(217)

=682 square meter

_____

cost of making road=rate * area of road =50*682==₹34,100

_____

thanks

Answer 2

Answer:

Are of road=Area of garden

including road - area of garden

π[49square-42square】

π[2401-1764]

=3.14×637=2000.18msquare

1m square cost=15

2000.18m square will cost =3000.7 rupee

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