Is CB || ED?
(1) ∆ABC and ∆AED are both isosceles triangles
(2) ∠C = ∠E
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tricky challenge question - Is CB || ED?
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Brent@GMATPrepNow
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Is CB || ED?
(1) ∆ABC and ∆AED are both isosceles triangles
(2) ∠C = ∠E
Brent Hanneson - Creator of GMATPrepNow.com
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GMATGuruNY
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Your Answer
A
B
C
D
E
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Statements combined:Brent@GMATPrepNow wrote:
Is CB || ED?
(1) ∆ABC and ∆AED are both isosceles triangles
(2) ∠C = ∠E
Case 1:
In this case, ∠B = ∠E and ∠C = ∠D, so CB || ED.
Case 2:
In this case, ∠B ≠∠E and ∠C ≠∠D, so CB ∦ ED.
Since the answer to the question stem is YES in Case 1 but NO in Case 2, INSUFFICIENT.
The correct answer is E.
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
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GMAT/MBA Expert
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Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
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Timer
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Your Answer
A
B
C
D
E
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Target question: Is CB || ED?Brent@GMATPrepNow wrote:
Is CB || ED?
(1) ∆ABC and ∆AED are both isosceles triangles
(2) ∠C = ∠E
Let's jump straight to....
Statements 1 and 2 combined
Statement 1 tells us that ∆ABC and ∆AED are both isosceles triangles
Statement 2 tells us that ∠C = ∠E
Let's start with 2 identical isosceles triangles:
If we arrange the triangles this way....
....we can see that the answer to the target question is YES, side CB IS parallel to side ED
HOWEVER, if we arrange the triangles this way....
....we can see that the answer to the target question is NO, side CB is NOT parallel to side ED
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT
Answer: E
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Brent
Brent Hanneson - Creator of GMATPrepNow.com
