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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?

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#### Solution

Cost of decorating the circumference = ₹ 16,940

Cost of decorating per meter = ₹ 55

∴ Length of the circumference = `16940/55 "m"` = 308 m

Circumference of the circular lawn = 308 m

2 × πr = 308 m

`2 xx 22/7 xx "r"` = 308 m

r = `(308 xx 7)/(2 xx 22)`

r = 49 m

Radius of the lawn = 49 m

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