The radius of a cylinder is doubled and its height is tripled. If its original volume was 10 cubic feet, what is its volume now, in cubic feet?
Cylinder volume = pi r^2 h
now double r and triple h
volume = pi (2r)^2 3h = pi 4r^2 3h= 12 pi r^2 h or 12 times the original volume 12 x 10 = 120 ft^3 (new volume)