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प्रश्न
If the base radius and the height of a right circular cone are increased by 20%, then the percentage increase in volume is approximately
पर्याय
60
68
73
78
उत्तर
The formula of the volume of a cone with base radius ‘r’ and vertical height ‘h’ is given as
Volume of cone = `1/3 pi r^2h`
= V
It is given that the base radius and the height are increased by 20%. So now the base radius is ‘1.2r’ and the height is ‘1.2h’.
So,
The volume of the modified cone =`1/3 pi(1.2r)^2(1.2h)`
`=1.728/3 pir^2 h`
= 1.728 V
Hence the percentage increase in the volume of the cone is 72.8%, which is approximately equal to 73%.
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