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On an aerial photograph, the surface of a pond appears as
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Author:  M8 [ 30 Apr 2006, 07:03 ]
Post subject:  On an aerial photograph, the surface of a pond appears as
On an aerial photograph, the surface of a pond appears as circular region of radius 7/16 inch. If a distance of 1 inch on the photograph corresponds to an actual distance of 2 miles, which of the following is the closest estimate of the actual surface area of the pond, in square miles?

A. 1.3
B. 2.4
C. 3.0
D. 3.8
E. 5.0

OPEN DISCUSSION OF THIS QUESTION IS HERE: on-an-aerial-photograph-the-surface-of-a-pond-appears-as-100605.html
Author:  Bunuel [ 21 Jul 2015, 01:42 ]
Post subject:  Re: On an aerial photograph, the surface of a pond appears as
M8 wrote:
On an aerial photograph, the surface of a pond appears as circular region of radius 7/16 inch. If a distance of 1 inch on the photograph corresponds to an actual distance of 2 miles, which of the following is the closest estimate of the actual surface area of the pond, in square miles?

A. 1.3
B. 2.4
C. 3.0
D. 3.8
E. 5.0


As 1 inch = 2 miles, then 7/16 inches = 2*7/16 = 7/8 miles. So actual radius is 7/8 miles. \(Area=\pi{r^2}\approx{\frac{22}{7}*\frac{49}{64}}\approx{2.4}\) (as we are asked about the approximate value we can take \(\pi\approx{\frac{22}{7}}\)).

Answer: B.

OPEN DISCUSSION OF THIS QUESTION IS HERE: on-an-aerial-photograph-the-surface-of-a-pond-appears-as-100605.html
Author:  ywilfred [ 02 May 2006, 00:25 ]
Post subject:  Re: On an aerial photograph, the surface of a pond appears as
7/16 inch = 7/16 * 2 = 7/8 miles.

Area = pi * r^2 = 22/7 * 7/8 * 7/8 = 77/32 = ~2.4
Author:  cdm2006 [ 01 May 2006, 03:22 ]
Post subject:  Re: On an aerial photograph, the surface of a pond appears as
B as well my estimate was: for r: 2*7/16= 7/8 and then 3*49/64= 150/64
Author:  sm176811 [ 03 May 2006, 03:18 ]
Post subject:  Re: On an aerial photograph, the surface of a pond appears as
Agreed... Answer is 2.4!

B...


Quote of the day: "Time to Charge Ahead!!"
Author:  shampoo [ 03 May 2006, 09:03 ]
Post subject:  Re: On an aerial photograph, the surface of a pond appears as
B. use the given ratio to convert the radius so, 7/8. area: (7/8)^2 * 3.
I heard we can use Pie=3 on gmat, is that true?
Author:  sm176811 [ 03 May 2006, 09:07 ]
Post subject:  Re: On an aerial photograph, the surface of a pond appears as
shampoo wrote:
B. use the given ratio to convert the radius so, 7/8. area: (7/8)^2 * 3.
I heard we can use Pie=3 on gmat, is that true?



I have seen different values used in different problems. I think it depends on the question and the values given to you. For some 22/7 works very nice as it cancels the given values!
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