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प्रश्न
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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उत्तर
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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