quadrant problem

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by Ganesh hatwar » Sun Aug 12, 2012 11:01 pm
princessss wrote:if ab does not equal 0, and (-a.b) and (-b,a) are in the same quadrant, is (-x,y) in this quadrant?

(1) xy>0
(2) ax>0
A .. A guess

xy>0 if both +ve or - ve

so when can know signs of both

ax> 0

Cant know sign of y

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by Ganesh hatwar » Sun Aug 12, 2012 11:05 pm
Rahul@gurome wrote:
sandysai wrote:Hi Rahul

if ab does not equal 0, and (-a.b) and (-b,a) are in the same quadrant, is (-x,y) in this quadrant?

(1) xy>0
(2) ax>0


Your earlier response:

"Combining (1) and (2), we get to know that x, y and a are all positive or all negative that x, y and a have the same sign"

I have QQ the above statement doesnt give any infernece abour B . To determin ( - x and y) lie in same co-ordinate, wht is there no dependency on "b" . How can we conclude with out considering b variable .?

Please throw some light on this one. Thanks!!
Let's start from the beginning again! :)

Given: ab does not equal zero, and (-a,b) and (-b,a) are on the same quadrant. These implies,
(i) Neither a nor b is equal to zero (As ab does not equal to zero).
(ii) As (-a,b) and (-b,a) are on the same quadrant. -a and -b should be of same sign. Thus, a and b are of same sign.

These information are available from the question itself.

Statement 1: xy > 0. This implies, x and y are of same sign. Nothing is said about their relation with a or b. So, this is NOT SUFFICIENT to determine whether (-x,y) is in the same quadrant.

Statement 2: ax > 0. This implies, a and x are of same sign. But nothing is mentioned about y. So, this is NOT SUFFICIENT to determine whether (-x,y) is in the same quadrant.

Now if we take both the statements together, we have the following information,
(i) a and b are of same sign. (From the question itself)
(ii) x and y are of same sign. (From Statement 1)
(iii) a and x are of same sign. (From Statement 2)

Combining these information, we get that a, b, x and y are of same sign. Therefore (-a,b), (-b,a) and (-x,y) are in the same quadrant. So, the statements together are sufficient.

The correct answer is C.


Hope this clears the confusions.
Hey thanks for the explanation

does it mean (-y,x) is also in same quadrant ?

Thanks

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by Ganesh hatwar » Sun Aug 12, 2012 11:07 pm
Ganesh hatwar wrote:
Rahul@gurome wrote:
sandysai wrote:Hi Rahul

if ab does not equal 0, and (-a.b) and (-b,a) are in the same quadrant, is (-x,y) in this quadrant?

(1) xy>0
(2) ax>0


Your earlier response:

"Combining (1) and (2), we get to know that x, y and a are all positive or all negative that x, y and a have the same sign"

I have QQ the above statement doesnt give any infernece abour B . To determin ( - x and y) lie in same co-ordinate, wht is there no dependency on "b" . How can we conclude with out considering b variable .?

Please throw some light on this one. Thanks!!
Let's start from the beginning again! :)

Given: ab does not equal zero, and (-a,b) and (-b,a) are on the same quadrant. These implies,
(i) Neither a nor b is equal to zero (As ab does not equal to zero).
(ii) As (-a,b) and (-b,a) are on the same quadrant. -a and -b should be of same sign. Thus, a and b are of same sign.

These information are available from the question itself.

Statement 1: xy > 0. This implies, x and y are of same sign. Nothing is said about their relation with a or b. So, this is NOT SUFFICIENT to determine whether (-x,y) is in the same quadrant.

Statement 2: ax > 0. This implies, a and x are of same sign. But nothing is mentioned about y. So, this is NOT SUFFICIENT to determine whether (-x,y) is in the same quadrant.

Now if we take both the statements together, we have the following information,
(i) a and b are of same sign. (From the question itself)
(ii) x and y are of same sign. (From Statement 1)
(iii) a and x are of same sign. (From Statement 2)

Combining these information, we get that a, b, x and y are of same sign. Therefore (-a,b), (-b,a) and (-x,y) are in the same quadrant. So, the statements together are sufficient.

The correct answer is C.


Hope this clears the confusions.
Hey thanks for the explanation

does it mean (-y,x) is also in same quadrant ?

Thanks
Also can it be solved by plugging numbers?

Kind Regards

Ganesh

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by chris558 » Fri Aug 17, 2012 5:10 am
princessss wrote:if ab does not equal 0, and (-a.b) and (-b,a) are in the same quadrant, is (-x,y) in this quadrant?

(1) xy>0
(2) ax>0
From the promt, we know that a and b have the SAME SIGN.
What we NEED to know to answer the question (Y/N) is whether x and y also have the same sign (their relationship between each other) and if either X or Y have the same sign as A or B.

1) Tells us that x and y have the same sign. Great, but we need to know their relationship to a and b. --> INSUFFICIENT

2) Tells us that A and X have the same sign. Great, but what about Y?

Combibined--> If x and y have the same sign, and a and x also have the same sign, this means that they ALL (a, b, x, & y) have the SAME sign. Therefore we can answer the question which is YES.

Answer: C

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by rajeshsinghgmat » Tue Feb 26, 2013 12:53 am
E in answer.

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by Java_85 » Fri Sep 20, 2013 8:35 am
IMO C it is,

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by [email protected] » Thu Dec 05, 2013 5:12 am
Hey Rahul,


Can you please show with a graph? for the mentioned data?

Thanks!


Rahul@gurome wrote:
sandysai wrote:Hi Rahul

if ab does not equal 0, and (-a.b) and (-b,a) are in the same quadrant, is (-x,y) in this quadrant?

(1) xy>0
(2) ax>0


Your earlier response:

"Combining (1) and (2), we get to know that x, y and a are all positive or all negative that x, y and a have the same sign"

I have QQ the above statement doesnt give any infernece abour B . To determin ( - x and y) lie in same co-ordinate, wht is there no dependency on "b" . How can we conclude with out considering b variable .?

Please throw some light on this one. Thanks!!
Let's start from the beginning again! :)

Given: ab does not equal zero, and (-a,b) and (-b,a) are on the same quadrant. These implies,
(i) Neither a nor b is equal to zero (As ab does not equal to zero).
(ii) As (-a,b) and (-b,a) are on the same quadrant. -a and -b should be of same sign. Thus, a and b are of same sign.

These information are available from the question itself.

Statement 1: xy > 0. This implies, x and y are of same sign. Nothing is said about their relation with a or b. So, this is NOT SUFFICIENT to determine whether (-x,y) is in the same quadrant.

Statement 2: ax > 0. This implies, a and x are of same sign. But nothing is mentioned about y. So, this is NOT SUFFICIENT to determine whether (-x,y) is in the same quadrant.

Now if we take both the statements together, we have the following information,
(i) a and b are of same sign. (From the question itself)
(ii) x and y are of same sign. (From Statement 1)
(iii) a and x are of same sign. (From Statement 2)

Combining these information, we get that a, b, x and y are of same sign. Therefore (-a,b), (-b,a) and (-x,y) are in the same quadrant. So, the statements together are sufficient.

The correct answer is C.


Hope this clears the confusions.