Is a/b>0?

IMO A
Stmt 1 tells a and b have opposite signs. So a/b<0. Sufficient

Stmt 2 tells a/b>0 or a/b<0

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Hi Aussy2000

Can you explain how Statement 2 proves that \(\frac{a}{b}>0\) ?

Hi Aussy

Statement 2 is actually NOT a definite yes. Its given that |a/b| > 0 or modulus of a/b is positive. For any non-zero number, its modulus will be positive only.

We can have say a=b=2, and so a/b = 2/2 =1 and |a/b| = 1. Here a/b > 0 and |a/b| is also > 0

But we can also have say a=-2 and b=2 and so a/b = -2/2 = -1 but |a/b| = 1. So here a/b < 0 but |a/b| >0

So we can't say whether a/b will be positive or negative on the basis of second statement.

Also in GMAT, whenever the answer is D, both statements give the same answer. So its NOT possible to get No from statement 1 and Yes from statement 2. If I ever come across such a case in my practice (different answers from the two statements) I know I am going off somewhere and I recheck.

Hi chetan2u

Can you explain why option A is incorrect and why C is correct choice here?

hi..
Typo.. ans is A .. Thanks
Kudos for pointing out

Thanks chetan2u for clarifying. I have been scratching my head for past half an hour to arrive at C

Hi chetan2u,

May be not worth asking, still...

From statement A, A+B=0, we could have A=B=0, So 0/0 ---Undefined ..... We don't know its +ve or -ve. Can we definitely arrive at a conclusion?

Hi chetan2u,

May be not worth asking, still...

From statement A, A+B=0, we could have A=B=0, So 0/0 ---Undefined ..... We don't know its +ve or -ve. Can we definitely arrive at a conclusion?[/quote]


Hi

Chetan will be best to answer this, but in my opinion, even if its not specified, we can ignore such things where we know its undefined. so eg - if its given that x/y > 2, we have to assume y not equal to 0, because otherwise the question stem becomes not defined. Similarly here I think we can safely assume that A and B will not be 0, because then A/B will become undefined.

Hi,

I had a question regarding the original statement. I was wondering if we can multiply b with 0 and can get the final equation as if a>0?

Thank You!

Hi..
No you cannot cross Multiply till you know that B is Positive..
If b is positive, a/b>0 will mean a>0..
If b is NEGATIVE, first multiply both sides by NEGATIVE to make statements POSITIVE.
Here a/b>0 will become a/b<0 if be is NEGATIVE and ao a<0..
Hope it helps you.

ManishKM1, sorry I missed out on your post..
It's ofcourse always better to mention that B is not equal to zero.

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