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Question
A cylinder with base radius of 8 cm and height of 2 cm is melted to form a cone of height 6 cm. The radius of the cone is
Options
4 cm
5 cm
6 cm
8 cm
Solution
Volume of cylinder `=pir^2h = pi xx (8)^2 xx 2= 128 pi cm^2`
Let r be the radius of cone
But,
The volume of cone = volume of cylinder
`1/3 pi r^2 h = 128pi`
`r^2 = (128 xx 3)/6 = 64`
r = 8 cm
Hence, Radius of cone = 8 cm.
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