A cylinder has its height doubled and its radius cut to 1/3. What is the ratio of the volumes of the modified cylinder to the original cylinder

Respuesta :

1 is to 4.5; the original cylinder was 3.14 and the modified cylinder was .698
(I ignored units)
let height of a cylinder is h and radius be r
volume of cylinder = πr*r*h
if height is doubled then height becomes =2h
radius becomes one third= 1/3 r
volume of cylinder becomes= π*1/3r*1/3r*2h =2/9πr*r*h
ratio of original cylinder to new one = 9/2