Question

Cylinder A has a radius of 12 inches and a height of 6 inches. Cylinder B has a volume of 648π. What is the percent change in volume between cylinders A and B?

Cylinder B is 50% smaller than cylinder A.
Cylinder B is 25% smaller than cylinder A.
Cylinder B is 150% bigger than cylinder A.
Cylinder B is 200% bigger than cylinder A.

Answer 1

find the volume of cylinder A

Answer 2

3.14 * 12^2 *6
3.14 * 144 *6
2712.96

Answer 3

yup, now find the volume of cylinder B

Answer 4

then divide the bigger volume by the smaller volume

Answer 5

then convert that decimal into a percent

Answer 6

but how do i find the volume of cylinder B when i dont know the radius

Answer 7

because it says the volume of cylinder B is 648 times pi

Answer 8

648 * 3.14 + 2034.72

Answer 9

no,volume of A\[=\pi 12^2*6=864 \pi\]
volume of B\[=648 \pi\]
change in volume\[=864 \pi-648 \pi=216 \pi\]
% change\[=\frac{ 216 \pi }{ 864 \pi }\times 100=25 % \]
=25 %

Answer 10

how did you get the volume of A to be 864.. Im confused ? @surjithayer

Answer 11

\[v= \pi r^2 h\]

Answer 12

he/she didn't get 864, he/she got 864*pi

Answer 13

Oh i see what you did now my bad(:

Answer 14

do not substitute the value of pi as the volume of B is 648 pi.

Answer 15

oh, never mind - listen to @surjithayer I might be wrong

Answer 16

i am a man.

Answer 17

I understand now, Thank you soooooo muchhh!!

Answer 18

yw