Question

The radius of the base of a circular cylinder 8s halved and height is doubled. What is the ratio of the volume of the new cylinder to that of the original cylinder

Answer 1

Let the radius of cylinder is r cm
And height is h cm
Then ,
New Radius = r/2
New height = 2h
Volume of the new cylinder/volume of old cylinder
$\frac{\pi ({ \frac{r}{2} })^{2}2h}{\pi {r}^{2}h } \\ \frac{ \frac{ {r}^{2} }{4}2h }{ {r}^{2}h } \\ \frac{2}{4} \\ \frac{1}{2} \: \:(ans)$