Questions about the world of GMAT Math from other sources and general math related questions.
AishwaryaK584
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Data sufficiency algebra

by AishwaryaK584 Sat Jun 21, 2014 12:53 pm

Hello

Question is if a>o is 2/a+b + 2/a-b= 1?

Statement 1 is : B=0
Statement 2 is : a^2 - b^2=4a

The answer is B.

I don't understand the solution to this problem. I looked at the explanation. Statement 2 is deemed as sufficient to answer the problem. why? We know that 4a= a sqaured- b squared. But how we can solve for this problem without knowing the exact value of B? I am confused as to how this is sufficient. my answer was C because knowing b=0 allows us to actually determine the value of A.


Thanks
RonPurewal
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Re: Data sufficiency algebra

by RonPurewal Wed Jun 25, 2014 4:14 am

Hello,

Per the forum rules, we need a citation of the original source of the problem. (Original authorship--not another forum or other secondary source.)

Thanks.
AishwaryaK584
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Re: Data sufficiency algebra

by AishwaryaK584 Fri Jun 27, 2014 1:56 pm

Hi

This came from the 6 CAT's i purchased for 35 bucks. Specifically its question 24 on my CAT2 test. Hope that clears it up. Thanks!
RonPurewal
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Re: Data sufficiency algebra

by RonPurewal Sun Jun 29, 2014 10:06 am

AishwaryaK584 Wrote:Hi

This came from the 6 CAT's i purchased for 35 bucks. Specifically its question 24 on my CAT2 test. Hope that clears it up. Thanks!


Hi,
If this problem is from a MGMAT CAT exam, then it belongs in the MGMAT CAT folder. So, here's what I'll do.
"- I'll give you some hints.
"- I'm going to lock the thread, since it's in the wrong folder.
"- If you still have trouble after I give you the hints, please post a new thread in the correct folder.

---

Hints:

"- (a^2 - b^2) is the product of (a + b) and (a - b).

"- Make a common denominator of the two fractions.

- Add the fractions.

- Using statement 2, you can transform that denominator into ... something else.

If there's still trouble, please post a new thread in the correct place. Thanks.