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The figure shows the top side of a circular medallion made

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Guest
 Post subject: The figure shows the top side of a circular medallion made
 Post Posted: Sun Aug 12, 2007 4:24 pm 
Please refer to the attached problem.

I think I know how to start the problem, but not sure how to reach an answer that fits the answers provided by the exam.

Answer = Area of Circular Medallion - Area of Circular Colored Glass = Area of Metal Frame

pie*r^2 - pie *(r - s)^2

= pie * r^2 - pie * r^2 - 2s + s^2

Is that correct so far? And how do I reach a final answer?

Thank you!
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Guest
 Post subject: Apologies - here is the attachment!
 Post Posted: Sun Aug 12, 2007 4:26 pm 
Image
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givemeanid
 Post subject:
 Post Posted: Sun Aug 12, 2007 6:32 pm 
YOu are on the right track. You just need to factorize a little more.

pi*r^2 - pi*(r - s)^2
= pi * r^2 - pi * (r^2 - 2rs + s^2)
= pi*r^2 - pi*r^2 + 2pi*r*s - pi*s^2
= 2pi*r*s - pi*s^2
= pi*s(2r - s)
= E
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Guest
 Post subject: Thanks!
 Post Posted: Mon Aug 13, 2007 11:33 am 
so close....clear explanation.

Thanks givemeanid.
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StaceyKoprince
 Post subject:
 Post Posted: Tue Aug 14, 2007 11:50 pm 
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ManhattanGMAT Staff


Posts: 6077
Location: San Francisco
Nice job once again, givemeanid. You've been a great help on the forums - keep up the good work!

_________________
Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT
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avlanib
 Post subject: Re: The figure shows the top side of a circular medallion made
 Post Posted: Thu Nov 12, 2009 4:44 am 
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Students


Posts: 1
What made you realize that "r" is the radius of the complete circle, encompassing the non shaded region and the shaded region? I thought r was radius of the the non shaded circle and s is the width of the frame(width of the shaded frame). So (r+s) was the complete circle radius and pi.r^2 is the radius of the inner circle.????

Please tell me this question is from the 700-800 difficutly level :)

Thank you for your help in advance.
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vimalshahmph
 Post subject: Re: The figure shows the top side of a circular medallion made
 Post Posted: Thu Nov 12, 2009 7:24 am 
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Posts: 5
in the question it clearly says that

figure is a top view of medallion made of circular glass surrounded by the frame.

the next line says radius of the medallion is r.........

if you take a good hard look...... you will figure it out......haste is waste while reading the problem.......

this would be a 600 level problem..........
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RonPurewal
 Post subject: Re: The figure shows the top side of a circular medallion made
 Post Posted: Fri Dec 18, 2009 5:37 am 
Offline
ManhattanGMAT Staff


Posts: 7146
vimalshahmph wrote:
in the question it clearly says that

figure is a top view of medallion made of circular glass surrounded by the frame.

the next line says radius of the medallion is r.........

if you take a good hard look...... you will figure it out......haste is waste while reading the problem.......

this would be a 600 level problem..........


remember, guys, there's little point in estimating the difficulty level of problems. even if you could somehow ascertain the precise difficulty level (which of course you can't), that's not the point.

the only "difficulty level" that matters - for a student studying for the exam - is "too easy for me / just right / too hard for me".
the only people who should care about numerical difficulty levels are people who write exams.

the point of studying these sorts of problems is to learn takeaways that you can take into other problems, a goal that is completely independent of the official difficulty level of the problem.
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