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InterviewSolution
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The diameter of one of the bases of a truncated cone is 100 mm. If the diameter of this base is increased by `21%` such that it still remains a truncated cone with the height and the other base unchanged, the volume also increases by `21%`. The radius the other base (in mm) isA. 65B. 55C. 45D. 35 |
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Answer» Correct Answer - B Let initially 2 bases have radii 5 cm and r cm. Finally base have radii `(1.21 xx 5)` and r Ratios of volumes = `(V_(2))/(V_(1))=1.21` `V_(2)=(pih)/3[(6.05)^(2)+(6.05)r+r^(2)]` `V_(1)=(pih)/3[5^(2)+5r+r^(2)]` `V_(2)/V_(1)=1.21 rArr((6.05)^(2)+(6.05)r+r^(2))/(5^(2)+5r+r^(2))` `rArr r^(2)=(6.3525)/21 ` `rArr r=11/2 cm = 55 mm` |
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