If the radius of the base of a cone is halved, keeping the height same, what is the ratio of the volume of the reduced cone to that of the original.

Explanation

let radius of cone `=r`

and height are`=h`

so new radius new radius `R=r/2`

their volume are` A& B` respectively

then `A/B={(1/3)pi(r^2)h}/{(1/3)pi((r/2)^2)h}`

`A/B=4/1`

so `B/A=1/4=1:4`