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The radius of the base of a right circular cylinder is doubled and the height is halved. What is the ratio of volume of the new cylinder to that of the original cylinder? - Mathematics

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प्रश्न

The radius of the base of a right circular cylinder is doubled and the height is halved. What is the ratio of volume of the new cylinder to that of the original cylinder?

योग

उत्तर

Let the radius of base of the original cylinder = r
And the height of the cylinder = h
Volume of original cylinder = π r2 h
Given that, the radius of new cylinder = 2r

And height= `"h"/(2)`

∴ Volume of new cylinder

= `π xx (2"r")^2 xx "h"/(2)`
= 2 x r2h
Ratio of volume of new cylinder to that of original cylinder

= `(2pi"r"^2"h")/(pi"r"^2"h")`
= 2 : 1.

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अध्याय 25: Surface Areas and Volume of Solids - Exercise 25.2

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फ्रैंक Mathematics [English] Class 9 ICSE
अध्याय 25 Surface Areas and Volume of Solids
Exercise 25.2 | Q 9

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