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# xy ≠ 0

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xy ≠ 0 [#permalink]  24 May 2017, 01:24
Expert's post
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Question Stats:

29% (01:09) correct 70% (00:50) wrong based on 31 sessions

$$xy ≠ 0$$

$$\frac{a}{xs}$$$$=632$$ and $$\frac{a}{ys}$$$$=158$$
 Quantity A Quantity B x y

A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
[Reveal] Spoiler: OA

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Director
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Re: xy ≠ 0 [#permalink]  10 Oct 2017, 08:48
We can derive the expression of x and y from the information we have and we get $$x = \frac{a}{632*s}$$ and $$y = \frac{a}{158*s}$$. Then, I would simplify the two expressions multiplying by s/a to get $$x = \frac{1}{632}$$ and $$y = \frac{1}{158}$$ and I would say B is greater. However the answer is D. How is it possible?
Intern
Joined: 27 Jul 2017
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Kudos [?]: 2 [0], given: 0

Re: xy ≠ 0 [#permalink]  10 Oct 2017, 10:06
IlCreatore wrote:
We can derive the expression of x and y from the information we have and we get $$x = \frac{a}{632*s}$$ and $$y = \frac{a}{158*s}$$. Then, I would simplify the two expressions multiplying by s/a to get $$x = \frac{1}{632}$$ and $$y = \frac{1}{158}$$ and I would say B is greater. However the answer is D. How is it possible?

S/a either (+) or (-), your case considered it only (+)value but if you go with (-) will get A is greater so that D is the right ans.
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Kudos [?]: 666 [2] , given: 147

Re: xy ≠ 0 [#permalink]  10 Oct 2017, 10:19
2
KUDOS
Carcass wrote:

xy ≠ 0

$$\frac{a}{xs}=632$$ and $$\frac{a}{ys}=158$$
 Quantity A Quantity B x y

Here $$\frac{a}{xs} =632$$

or a = 632xs

And from 2nd equ we have

a= 158ys

Therefore we can write as -
632xs=158ys

or y/x = 4

There fore one possible way can be possible

if x=1 and y= 4 , therefore x<y

or if x = -1 and y = -4, therefore x>y

These both values are possible, since the question didnot mentioned that both x and y are positive

Hence option D
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Re: xy ≠ 0   [#permalink] 10 Oct 2017, 10:19
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# xy ≠ 0

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