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Source: — Problem Solving |

by shankar.ashwin » Mon Sep 26, 2011 4:37 am
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by Anurag@Gurome » Mon Sep 26, 2011 4:51 am
gunjan1208 wrote:Could somebody help me finding the explanation:-->
Since angle BDC = angle BCD, so side BD = BC.
In triangle ABD, angle ADB + 2x = 180
Also, x + angle ADB + angle ABD = 180
So, angle ADB + 2x = x + angle ADB + angle ABD
x = angle ADB, which implies triangle ABD is an isosceles triangle with AD = BD.
Since AD = BD = BC, so the question is: What is AD?

(1) AD = 6; SUFFICIENT.
(2) x = 36 does not give us any lengths; NOT sufficient.

The correct answer is A.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

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