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Source: — Data Sufficiency |
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by shanrizvi » Sat Aug 29, 2009 2:04 pm
It is either B or C. You may be able to answer the question with just B but I don't know how to.
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by PussInBoots » Sat Aug 29, 2009 7:52 pm
The answer is B, angle BDC = x, DBC = 180 - 2x, hence ABD = 2x. BC = BD = AD
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by bharathh » Sat Aug 29, 2009 9:13 pm
How do you know BDC is x from knowing AD is 1?
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by capnx » Sat Aug 29, 2009 9:16 pm
sides BC = BD, so their angles must also equal. match all the angles, then trace back the sides that are the same
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by bharathh » Sat Aug 29, 2009 9:23 pm
Doh .. didn't read the question properly.

Ok then my answer is B

With Statement 1 you can prove that AD:DC = 1:2, but you need the value of AD to know for sure.

With statement 2 you can prove that BC is 1
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by Bhavin@Magoosh » Sun Aug 30, 2009 6:54 am
Good work! OA is B.

We know BDC is x (because side BC = BD)
Therefore DBC is 180-2x
Therefore DBA is 2x, making triangle ABD isosceles
Therefore side AD = side BD (and we know BD = BC)

So B is sufficient.
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