If the radius of a cylinder is doubled and so is the height, what is

Question

If the radius of a cylinder is doubled and so is the height, what is the new volume of the cylinder divided by the old one?

A. 8.
B. 2.
C. 6.
D. 4.
E. 10.

FacelessMan · Answer

let the radius be r and the the height be h.
New radius = 2r and height = 2h.

Area (new) : Area(old) =  pi*(2r)^2*2h/pi*r^2*h  = 8:1. Hence the answer is A.

CounterSniper · Answer

let v and v' be the original and the changed volume
now
v=pir^2h
v'=pi(2r)^2(2h)
v'=8v

ashwini86 · Answer

A,

Doubling of radius is 2r and heaight is 2h

new volume = pi*(2r)^2*2h = 8*pi*h*r^2

rhine29388 · Answer

Volume of the cylinder =  \pi   r^2 h
if the radius is doubled then new radius would be 2r 
height is doubled so the new height is 2h
new volume =  \pi  *  (2r)^2 *2h = 8  \pi  r^2 h = 8 * original volume of the cylinder
Correct Answer - A

ScottTargetTestPrep · Answer

We are give that both the radius and height of a cylinder are doubled. If we let r = radius of the cylinder and h = height of the cylinder, then the original volume of the cylinder is:

V(old) = π(r^2)h

Since the radius and height are doubled, the new volume is:

V(new) = π(2r)^2 x (2h) = π(4r^2)(2h) = 8π(r^2)h

Thus, new volume/old volume =  /  = 8.

Answer: A

If the radius of a cylinder is doubled and so is the height, what is

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If the radius of a cylinder is doubled and so is the height, what is

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