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Two cylinders have radii in the ratio 3:5 and heights in the ratio 10:9. Find the ratio oftheir volumes. |
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Answer» Answer: Suppose that two right circular SOLID cylinders A with radius r and HEIGHT h and B with radius R and height Hthen Ratio of radii r:R=3:5 Let r=3x and R=5x Ratio of heights =h:H=2:3 Let h=2y and H=3y CURVED Surface Area of cylinder A=2πrh=2π(3x)(2y)=12πxy Curved Surface Area of cylinder B=2πRH=2π(5x)(3x)=30πxy Ratio of their Curved Surface Area of A and B= 30πxy 12πxy
= 5 2
Hence, the ratio of the curved surface areas of cylinders is 2:5. Volume of cylinder A=πr 2 h=π(3x) 2 (2y)=18πx 2 y Volume of cylinder B=πR 2 H=π(5x) 2 (3y)=75πx 2 y Ratio of the Volume of A and B= 75πx 2 y 18πx 2 y
= 25 6
Hence, the ratio of the volumes of cylinders is 6:25. Hope this helps you mate! |
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