Question

in a cylinder,if radius is halved and height is doubled, then find its volume

Answer 1

let the radius be r and height  be h
volume = $\pi r^{2} h$
if the radius is halved then radius = r/2
and height is doubled ,so height= 2h

volume =[$\pi r*r/4*2h$
             = $\pi *r ^{2} *h/2$

hence the volume will be halved

Answer 2

volume of the cylinder is πr²h
hear the question is radius is halved it means
radius =r/2
height is doubled it means
height =2h
volume of cylinder = 22 /7 x (r/2)x(r/2) x 2h
then volume of cylinder will be 1/2πr²h