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प्रश्न
A gardener wants to fence a circular garden of diameter 21 m. Find the length of the rope he needs to purchase, if he makes 2 rounds of fence. Also find the costs of the rope, if it cost ₹ 4 per meter. (Take `pi = 22/7`)
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उत्तर
d = 21 m
r = `21/2` m
Circumference = 2πr
= `2 xx 22/7 xx 21/2`
= 66 m
Length of rope required for fencing = 2 × 66 m
= 132 m
Cost of 1 m rope = ₹ 4
Cost of 132 m rope = 4 × 132
= ₹ 528
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