If x != -y, is (x-y)/(x+y) > 1
1. x>0
2. y<0
I found this one confusing! Can anyone give an explanation for this with working out?
I tried searching the forum for this but couldn't find it - possibly since there are a tonne of posts with x's and y's in them!
GMATPrep2: If x != -y, is (x-y)/(x+y) > 1
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I feel the ans is A
x-y/x+y>1
i.e x-y-x-y/x+y>0
i.e -2y/x+y>0
or y/x+y <0
nw we nw factorial of of a number is >0 therefore , y hat to be negative
also x therfore will be +ve
nw for y/x+y will be <0 if y<0 and x+y >0
or y>0 and x+y<0
we nw only the first condition will hold i.e y<0 and x+y>0
the first statement says x>0 , that
actually x would in all but two cases 1! and 2! will be less than y in magnitude , in which case x+y <0 but x can be equal to y and then
in either case y/x+y>0
answer will be infinity which is greater than 0
second statement says y <0 , that we already knw ,
x-y/x+y>1
i.e x-y-x-y/x+y>0
i.e -2y/x+y>0
or y/x+y <0
nw we nw factorial of of a number is >0 therefore , y hat to be negative
also x therfore will be +ve
nw for y/x+y will be <0 if y<0 and x+y >0
or y>0 and x+y<0
we nw only the first condition will hold i.e y<0 and x+y>0
the first statement says x>0 , that
actually x would in all but two cases 1! and 2! will be less than y in magnitude , in which case x+y <0 but x can be equal to y and then
in either case y/x+y>0
answer will be infinity which is greater than 0
second statement says y <0 , that we already knw ,
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well if not A , it must be E , thats because the case of infinity being greater >0 was ambigious to me ,
anyway let some other try .....even I am confused ......
anyway let some other try .....even I am confused ......
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IMO the answer is E
Statement 1
we get that X>0 but we do not know the value of Y
If X=3 and Y=-2 then (X-Y)/(X+Y)> 1
But if X=3 and Y=-5 then (X-Y)/(X+Y)<1
Statement 2
Y<0
Same reasoning as for statement 1
When we combine both we don't know the relation between X and Y.........hence we cannot get an answer...........
Statement 1
we get that X>0 but we do not know the value of Y
If X=3 and Y=-2 then (X-Y)/(X+Y)> 1
But if X=3 and Y=-5 then (X-Y)/(X+Y)<1
Statement 2
Y<0
Same reasoning as for statement 1
When we combine both we don't know the relation between X and Y.........hence we cannot get an answer...........
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hi gautamberry,
the statement says x! = -y hence the examples that you have taken are incorrect
when x= 3 y = -6 because x! = 6
the statement says x! = -y hence the examples that you have taken are incorrect
when x= 3 y = -6 because x! = 6
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question asks
is (x-y)/(x+y) >1
unfortunately we can not simplify this as we do not know sign of (x+y)
stmt 1 and 2 alone is not sufficient for obvious reasons that each omits either x or y
together they are agin insuff
take x =1 y = -2
then (x-y)/(x+y) == 3/(-1) < 1
but if x =10 and y =-2
then (x-y)/(x+y) = 12/8 >1
hence insufficient.
answer is E.
what is OA?
is (x-y)/(x+y) >1
unfortunately we can not simplify this as we do not know sign of (x+y)
stmt 1 and 2 alone is not sufficient for obvious reasons that each omits either x or y
together they are agin insuff
take x =1 y = -2
then (x-y)/(x+y) == 3/(-1) < 1
but if x =10 and y =-2
then (x-y)/(x+y) = 12/8 >1
hence insufficient.
answer is E.
what is OA?
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it can't be anything other than 'E'.cubicle_bound_misfit wrote:
take x =1 y = -2
then (x-y)/(x+y) == 3/(-1) < 1
but if x =10 and y =-2
then (x-y)/(x+y) = 12/8 >1
hence insufficient.
answer is E.
what is OA?
if x>0 and y<0, x-y will always be positive.
now x+y can be positive or negative. When x+y is positive the expression is always greater than 1 and when negative it is obv. less than 1.
Shahid E
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cubicle_bound_misfit :
I always have this problem : when to simplify the given equation and when not to?
for example, in the above question I simplified the equation to:
y<0
since the first choice is x>0,
and since we have derived y<0;
(x-y) / (x+y) => will be like (x+y) /(x-y)
there fore surely, this will be greater than 1.
So my choice was A.
But you say that: this equation cannot be simplified, since we dont know the sign of (x+y) - denominator.
Can you please throw more light on this?
I always have this problem : when to simplify the given equation and when not to?
for example, in the above question I simplified the equation to:
y<0
since the first choice is x>0,
and since we have derived y<0;
(x-y) / (x+y) => will be like (x+y) /(x-y)
there fore surely, this will be greater than 1.
So my choice was A.
But you say that: this equation cannot be simplified, since we dont know the sign of (x+y) - denominator.
Can you please throw more light on this?
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msvmuthu- I replied to your question here (another thread about the same question)
https://www.beatthegmat.com/inequalities-t20825.html
(edited to fix the link)
https://www.beatthegmat.com/inequalities-t20825.html
(edited to fix the link)
Last edited by Ian Stewart on Mon May 25, 2009 8:07 pm, edited 1 time in total.
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