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प्रश्न
The curved surface area of a cylinder is reduced by ______ per cent if the height is half of the original height.
उत्तर
The curved surface area of a cylinder is reduced by 50 per cent if the height is half of the original height.
Explanation:
The curved surface area of a cylinder with radius r and height h = 2πrh
If the height is halved, then new curved surface area of cylinder = `2pir h/2 = pirh`
∴ Percentage reduction in curved surface area = `(2pirh - pirh)/(2pirh) xx 100`
= `(pirh)/(2pirh) xx 100`
= 50%
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