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magical cook
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 Posted: Mon Jan 21, 2008 10:03 am Post subject: triangle |
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Hi,
I think answer should be B but want to know how to get the length of b..
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StarDust845
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| Posted: Mon Jan 21, 2008 2:41 pm Post subject: |
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Answer is B.
(1) is useless because we can derive the same from the diagram given.
But well, you can write down the equations and see that is not possible to extract "b" out of it.
So either answer is B or E.
(2) a = sqrt(84).
but bc = 5a (we can derive this from the diagram itself, no need to go to (1). Angle QPR = Angle EQR. Assume E is the point of intersection of PR and the line dropping from Q. As they are similar traingles we get 5/b = c/a)
The way to go about calculating b is simple. c^2 - b^2 = 25. -> (A)
And you know c in terms of "a" and "b" in which "a" is known. Hence you can reduce above equation just in terms of "b". Solve for b.
Calista.
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gmatguy16
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| Posted: Tue Jan 22, 2008 6:26 pm Post subject: |
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stuart,
in questions like this should we assume that the point . is the center of the circle unless mentioned.
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Stuart Kovinsky
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| Posted: Tue Jan 22, 2008 6:39 pm Post subject: |
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| gmatguy16 wrote: | stuart,
in questions like this should we assume that the point . is the center of the circle unless mentioned. |
The . is the centre of the circle by convention, so yes, you can make that assumption (although on the actual GMAT they'll almost always explicitly state that as well).
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StarDust845
Really wants to Beat The GMAT!
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Test Date: Jan 29th.
Target GMAT Score: 700+
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| Posted: Tue Jan 22, 2008 6:40 pm Post subject: |
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| Good question. Otherwise I don't think we will know the answer.
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