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

@ganeshie8

Answer 2

@ganeshie8

Answer 3

First, find the volume of cylinder A.

Answer 4

Do you know how to find the volume of a cylinder?

Answer 5

The volume of cylinder A is 2,712.96

Answer 6

\(\Large V_{cylinder} = \pi r^2 h\)

where r = radius of the base, and
h = height of the cuylinder

Answer 7

Yea so the volume of cylinder A is 2,712.96

Answer 8

So what do I do now?

Answer 9

Correct.
Since the volume of cylinder B is written in terms of pi, you can also write the volume of cylinder A in terms of pi. (In other words, don't multiply pi in the formula.)

\(\Large V_{A} = 864 \pi\)

\(\Large V_B = 648 \pi\)

Ok so far?

Answer 10

Yes mam or sir

Answer 11

Would you divide Va by Vb and then multiply it by 100...

Answer 12

Now we need the second step of the problem. We need to find the percent change. Look in all choices. Every choice states "Cylinder B is ... than cylinder A."
This means we are comparing cylinder B to A.

Answer 13

Here is the formula to calculate percent change:

\(percent~change = \dfrac{new~amount - old~amount}{old~amount} \times 100\)

If the percent change is positive, it is an increase. If the percent change is negative, it is a decrease.

In this case, since we are comparing cylinder B to cylinder A, then
old amount = 864 pi
new amount = 648 pi
(pi will cancel out in the calculation.)

Answer 14

So will it be 25% smaller then cylinder A right?

Answer 15

Correct.

Answer 16

Yayyyy Thank You!!! @mathstudent55

Answer 17

You're welcome.