If the radius of a right circular cylinder is doubled and the height

Question

If the radius of a right circular cylinder is doubled and the height is tripled, how does the volume of the cylinder change?

A. It is 2 times as much as before.

B. It is 4 times as much as before.

C. It is 3 times as much as before.

D. It is 6 times as much as before.

E. It is 12 times as much as before.

DavidTutorexamPAL · Answer

As there is an exact equation for the volume of a cylinder, we'll use it.
This is a Preicse approach.

The volume of a cylinder is the area of its base multiplied by its height.
Increasing the radius by a factor of 2 increases the area by a factor of 4.
So, our total volume is increased by the area * height = 4*3 = 12.

(E) is our answer.

EgmatQuantExpert · Answer

Solution

To find:  
 • The change in volume of a cylinder, if radius is doubled and height is tripled

Approach and Working:   
For any given right-circular cylinder, volume is directly proportional to:
 • Square of radius
• Height  
Therefore, if radius is doubled, volume will become 4 times
Similarly, if height is tripled, volume will become 3 times

• Total change in volume = 4 * 3 = 12 times as much as before

Hence, the correct answer is option E.

Answer: E

Tulkin987 · Answer

V=\pi  r^2  h

New volume  =\pi  (2r)^2  (3h)  =12*\pi  r^2  h

Answer: E

generis · Answer

Volume, V, of a cylinder =  \pi r^2 h

Assign values. (Simplest is to start with r=1 and h=1. I chose r=2 from sheer whimsy.)

Cylinder 1:  r = 2, h = 1 
 V_1=\pi r^2h=(\pi*4*1) = 4\pi

Cylinder 2: radius doubles, height triples 
 r=4,h=3 
 V_2=(\pi*16*3)=48\pi

How does volume of cylinder change?
 \frac{48 \pi}{4 \pi}=12  times as much as before

Answer E

ScottTargetTestPrep · Answer

The initial volume is πr^2h.

The new volume is π(2r)^2(3h) = π4r^2 x 3h = 12πr^2h

Comparing the new volume of 12πr^2h to the original volume of πr^2h, we see that the new volume is 12 times the original volume.

Answer: E

LeoN88 · Answer

Original Volume= PI(r^2)h
New Volume=PI(4)(r^2)(3)(h)= 12 times the original volume.  E

If the radius of a right circular cylinder is doubled and the height

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If the radius of a right circular cylinder is doubled and the height

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