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Is a=b? 1) \(a^2=b^2\) 2) \(a=2\)
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Last edited by Bunuel on 24 Feb 2017, 07:01, edited 1 time in total.
Edited the OA.



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Re: Is a=b? [#permalink]
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24 Feb 2017, 02:48
(1) a^2 = b^2; Suppose, a = 2, and b = 2, Therefore, a = b;
Again, suppose a= 2 and b = 2; In this case also a^2 = b^2 is true, but a ≠ b; Hence, Insufficient.
(2) a = 2; Insufficient;
(1) And (2) together, Insufficient;
Answer E.



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Re: Is a=b? [#permalink]
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24 Feb 2017, 06:45
MathRevolution wrote: Is a=b?
1) \(a^2=b^2\) 2) \(a=2\) Hi BunuelCan throw some light on this question Seems like ans is E. Can you validate.
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Re: Is a=b? [#permalink]
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24 Feb 2017, 06:50
MathRevolution wrote: Is a=b?
1) \(a^2=b^2\) 2) \(a=2\) In statement 1, If a^2 = b^2, then b can be equal to a or b can be equal to a because a^2 is also equal to (a)^2. Hence insufficient In statement 2, a = 2, but there is no information of b. Hence, insufficient By combining, if a = 2, then a^2 is 4. But b can be 2 or 2 because 2^2 = 4 and (2)^2 is also 4. Hence, together also insufficient. Thanks, Anant Saraogi



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Re: Is a=b? [#permalink]
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24 Feb 2017, 06:53
NandishSS wrote: MathRevolution wrote: Is a=b?
1) \(a^2=b^2\) 2) \(a=2\) Hi BunuelCan throw some light on this question Seems like ans is E. Can you validate. You're right; the correct answer is E Statements 1 and 2 combined Case a: a = 2 and b = 2, in which case a EQUALS bCase b: a = 2 and b = 2, in which case a DOES NOT EQUAL bSince we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT Cheers, Brent
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Re: Is a=b? [#permalink]
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24 Feb 2017, 17:34
GMATPrepNow wrote: NandishSS wrote: MathRevolution wrote: Is a=b?
1) \(a^2=b^2\) 2) \(a=2\) Hi BunuelCan throw some light on this question Seems like ans is E. Can you validate. You're right; the correct answer is E Statements 1 and 2 combined Case a: a = 2 and b = 2, in which case a EQUALS bCase b: a = 2 and b = 2, in which case a DOES NOT EQUAL bSince we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT Cheers, Brent Thank you Brent Sent from my AO5510 using GMAT Club Forum mobile app
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Re: Is a=b? [#permalink]
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26 Feb 2017, 20:32
==> In the original condition, there are 2 variables (a,b) and in order to match the number of variables to the number of equations, there must be 2 equations. Since there is 1 for con 1) and 1 for con 2), C is most likely to be the answer. By solving con 1) and con 2), from a=2, you get \(b^2=2^2=4\), then b=±2. Thus, (a,b)=(2,2) yes but (a,b)=(2,2) no, hence it is not sufficient. The answer is E. Answer: E
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