What is the volume of the cylinder?

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What is the volume of the cylinder?

by AAPL » Thu Jan 04, 2018 2:16 pm
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A four inch by four inch square sheet of paper was foled to form a cylinder, as shown above. What is the volume of the cylinder?

A. 16/Ï€
B. 16
C. 64/Ï€
D. 16Ï€
E. 64Ï€

The OA is A.

I know that the volume of a cylinder can be determine by,
$$A_{cylinder}=\pi\cdot r^2\cdot h$$
But, I don't know how can I get the value of r.

I appreciate if any expert explain this PS question for me. Thank you so much.

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by DavidG@VeritasPrep » Thu Jan 04, 2018 2:23 pm
AAPL wrote:Image

A four inch by four inch square sheet of paper was foled to form a cylinder, as shown above. What is the volume of the cylinder?

A. 16/Ï€
B. 16
C. 64/Ï€
D. 16Ï€
E. 64Ï€

The OA is A.

I know that the volume of a cylinder can be determine by,
$$A_{cylinder}=\pi\cdot r^2\cdot h$$
But, I don't know how can I get the value of r.

I appreciate if any expert explain this PS question for me. Thank you so much.
Imagine rolling that square of paper into the cylinder. The top side of the square will be the same as the circumference of the circle once you form the cylinder. If the circumference of the circle is 4, then we can simply solve C = 2Ï€r = 4 --> r = 2/Ï€. From there, it's just plug and chug with the cylinder formula.
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by Scott@TargetTestPrep » Mon Sep 02, 2019 5:58 pm
AAPL wrote:Image

A four inch by four inch square sheet of paper was foled to form a cylinder, as shown above. What is the volume of the cylinder?

A. 16/Ï€
B. 16
C. 64/Ï€
D. 16Ï€
E. 64Ï€
volume of the cylinder = (Ï€)(radius)^2(height)

When the paper is wrapped to form the cylinder, the 4-inch side of the square becomes the circumference of the circle. Thus, we have:

2Ï€r = 4, so r = 2/Ï€.

Thus:

volume = (Ï€)(2/Ï€)^2(4)

volume = (Ï€)(4/Ï€^2)(4)

volume = 16/Ï€

Answer: A

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by Scott@TargetTestPrep » Mon Sep 02, 2019 5:58 pm
AAPL wrote:Image

A four inch by four inch square sheet of paper was foled to form a cylinder, as shown above. What is the volume of the cylinder?

A. 16/Ï€
B. 16
C. 64/Ï€
D. 16Ï€
E. 64Ï€
volume of the cylinder = (Ï€)(radius)^2(height)

When the paper is wrapped to form the cylinder, the 4-inch side of the square becomes the circumference of the circle. Thus, we have:

2Ï€r = 4, so r = 2/Ï€.

Thus:

volume = (Ï€)(2/Ï€)^2(4)

volume = (Ï€)(4/Ï€^2)(4)

volume = 16/Ï€

Answer: A

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

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