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If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:00
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If \(xy^2z^3 < 0\), is \(xyz>0\)? (1) \(y < 0\) (2) \(x < 0\)
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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:20
If xy2z3<0xy2z3<0, is xyz>0xyz>0? (1) y<0y<0 (2) x<0 E has to be the answer. Because we have to know the value of both X and Z
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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:25
Stmt 1 is y is squared power does value does not matter as it will always be positive. not sufficient stmt 2) x is ve y always positive z? not sufficient together both also not sufficient as z can be positive or negative.



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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:26
IMO : A
If
xy^2z^3<0 , is xyz>0?
(1) y<0
(2) x<0
Sol:
from the give info we know that either x or z is negative because y^2 cannot be negative.
so
from 1) y<0 tell that two from x,y,or z is negative that means xyz>0
sufficinet.
2)x<0 we cant say anything about y, if y is <0 then the value become positive and if y>0 then the value becomes negative.
So A is sufficient.



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If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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Updated on: 23 Jul 2019, 09:33
Quote: If xyˆzˆ3<0, is xyz>0?
(1) y<0 (2) x<0 xyˆzˆ3<0: this means that x and z are different signs and all are ≠ 0. [1] x>0 and z<0: +()=()… ()y>0, y must be negative; [2] x<0 and z>0: ()+=()… ()y>0, y must be negative; (1) y<0; sufficient. (2) x<0; we need y, insufficient. Answer (A).
Originally posted by exc4libur on 23 Jul 2019, 08:29.
Last edited by exc4libur on 23 Jul 2019, 09:33, edited 1 time in total.



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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:31
IMO answer is A:
given xy^2z^3 <0 as y^2>0, xz^3<0, this implies x and z have opposite signs. xz<0 we only need sign of y to know the result xyz > 0 or xyz <0
from1:directly get y<0 suff from2: not suff, all we know is sign of z from this



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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:35
Quote: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0 By given equation we know, either x<0 or z <0 By 1, y<0 and either x<0 or z <0, hence xyz>0. Sufficient. By 2, we have no info about y. Insufficient. Hence A
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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:36
If\(xy^2z^3<0\), is xyz>0?
(1) y<0 (2) x<0
given \(xy^2z^3<0\) thus \(xz^3<0\) as y^2 will always be positive. to determine \(xyz>0\), we can check if \(y<0\) then ()() will make positive as xz is also zero (1) y<0 thus this will make entire expression positive hence sufficient (2) x<0 No help as we know either x or z sign make no use to us. We need y sign Hence not sufficient Thus answer is A



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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:39
If xy2z3<0, is xyz>0?
This is an easy question. Before we see the options, let's understand the question. We are given that xy2z3<0
Which means that Y^2 is positive so for xy2z3<0 to be negative either of X or Z is negative.
Now for us to prove xyz>0, We have two options either all are positive or two are negative and 1 is positive. The first option is out as we know that either of X or Z is already negative. So we are now looking if Y is negative or not.
Let's get to POE.
(1) y<0 This is exactly what we are looking for this proves us that XYZ > 0. Hence this is sufficient.
(2) x<0 This is not sufficient alone as we already knew that X/ Z is going to be negative, the result still depends on Y.
Hence the answer is A.



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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:40
A.
We are basically given xz<0, so for xyz>0 , we need y<0
St 1: y <0 sufficient St 2: x<0 doesn't help. Not sufficient
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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:43
The answer is A.
This is a question about positives and negatives.
If xy2z3<0, is xyz>0?
(1) y<0 (2) x<0
Since y2 is always positive, for xy2z3 to be negative, then either x or z has to be negative (either one, not both). Also, to answer the question of is xyz positive, since we know either x or z are negative (there is already a negative there), we need to know whether y is positive or negative to answer the question.
From (1) we know that y is negative. Since y is negative, then we can answer that xyz is positive "Yes" based on the conditions above. We don't need to know which variable X or Z is negative, we just need to know that y is negative to answer, so 1 is sufficient.
From (2) alone, we don't know anything about whether y is positive or negative so we can't answer the question. 2 is insufficient.
So answer is A.



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If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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Updated on: 23 Jul 2019, 22:38
\(x*y^2*z^3\)= negative Thus, x and z will always have opposite signs. > (a) Also none of x, y and z equals to 0.
We need to find whether the product of xyz is positive.
(1) y < 0 When x is +ve and z is –ve: xyz > 0
When x is –ve and z is +ve: xyz > 0
Sufficient
(2) x<0 Given x is –ve, so from (a) z is +ve
When y < 0 xyz > 0
When y > 0 xyz < 0
Not Sufficient
Answer A
Originally posted by Sayon on 23 Jul 2019, 08:43.
Last edited by Sayon on 23 Jul 2019, 22:38, edited 1 time in total.



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If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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Updated on: 24 Jul 2019, 11:01
If xy2z3<0, is xyz>0?
(1) y<0 (2) x<0
from given info we can say that either x or z is ve and y may be ve which makes xy2z3<0 #1 y<0 ; either of x or z is ve so sufficient that xyz>0 is possible #2 x<0 dont know about y and z so insufficient
IMO A
Originally posted by Archit3110 on 23 Jul 2019, 08:44.
Last edited by Archit3110 on 24 Jul 2019, 11:01, edited 1 time in total.



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If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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Updated on: 24 Jul 2019, 03:50
If \(xy^{2}z^{3}<0\), is xyz>0
Since \(y^{2}\) is always > 0 => \(xz^{3}<0\). \(z^{3}\) will have the same sign as z, therefore xz<0 Therefore, to find out about xyz, we need to know the sign of y.
(1) y<0, y sign is given, therefore sufficient (2) x<0, y sign is not given, therefore insufficient
Answer is A
Originally posted by berdibekov on 23 Jul 2019, 08:46.
Last edited by berdibekov on 24 Jul 2019, 03:50, edited 1 time in total.



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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:52
x.y^2.z^3 <0 ==> x.z^3<0 ==> x.z<0
To find whether xyz>0 we already have x.z<0
Ask is to only find whether y is positive or negative.
Statement 1 is sufficient
Hence, A is the answer.



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If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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Updated on: 23 Jul 2019, 08:57
Given: \(xy^2z^3<0\) Asked; Is xyz>0 \(xy^2z^3<0\) => x,y,z are nonzero numbers xz<0 since \(y^2z^2\) is always positive For xyz>0 Since xz<0 => y<0 for xyz>0 (1) y<0 Since y<0 => xyz>0 since xz<0 and y<0 SUFFICIENT (2) x<0 If x<0 => z>0 but there is no information about y NOT SUFFICIENT IMO A
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Originally posted by Kinshook on 23 Jul 2019, 08:56.
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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:56
If x*(y^2)*z^3<0, is xyz>0?
From the given inequality we can conclude that since y has power 2, it is always positive. This means that x*z<0, either x positive and z negative or x negative and z positive. We are asked whether xyz is positive. Since we already know that xy<0 all we need is the value of y.
(1) y<0
Sufficient, as stated above.
(2) x<0
Not sufficient. We don't need to know the value of x.
IMO A



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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 08:59
\(y^{2}\) must be positive. Since x\(y^{2}\)\(z^{3}\) is negative, then either x or z is negative, however, both cannot be negative or the total product would be positive. We don't need to know if x or z is negative or positive since we know one or the other is. If we know y is negative then we know the overall total must be positive (two negatives * one positive = positive total). A



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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 09:04
Upon analyzing the question stem, we can infer that X & Z are of different signs, since the product of y^2 (+ve), X & Z is negative.
Statement 1
Y is negative. then the product of XZ (ve) and Y (ve) will be positive.
Statement 2
X is negative. Then, we know that Z is +ve but we cannot further conclude whether product of XYZ will be negative. Case 1. XZ (ve) & Y (ve) = +ve
Case2. XZ (ve) & Y (+ve) = ve (2) x<0x<0



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Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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23 Jul 2019, 09:11
Our answer is going to be affected by 3 cases to prove if xyz >0 : x y z + +  = result will be xyz <0  + + = result will be xyz < 0 + + + = result will be xyz >0 Have taken y positive as y^2 : will always be positive So we need all 3 x,y,z > 0 to prove question stem
Statement 1 : y <0 : It actually doesn't have any effect because its going to be positive in any case: So in sufficient Statement 2 : As discussed, we also need to know what is z which is not given : x < 0 gives 2 results , so insufficient
Combining 1 and 2 : Still we don't have any information for Z , so Option E




Re: If xy^2z^3 < 0, is xyz>0? (1) y < 0 (2) x < 0
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