gmat prep question

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gmat prep question

by yvonne12 » Fri Apr 20, 2007 3:02 pm
the figure above shows the top side of a circular medallion made of circular piece of colored glas sorrounded by a metal frame, represented by the shaded region. If the radius of the medallion is r centimeters and the width of the metal frame is s centimeter , then in terms of s and r , what is the area of the metal frame in square centimeters?

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by Tame the CAT » Sat Apr 21, 2007 7:39 am
where is the figure?

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gmat prep question

by yvonne12 » Sat Apr 21, 2007 10:49 am
picture a circle with a metal frame around it.

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by Cybermusings » Sun Apr 22, 2007 5:13 am
Since the figure is not there...I am pre-supposing that the radius of the medallion (minus the frame) is r

Area of medallion = pie*r^2
Area of medallion + frame = pie*(r+s)^2
So area of frame alone = pie*(r+s)^2 - pie*r^2
= pie*s^2 - 2*pie*r*s