December 15, 2018 December 15, 2018 07:00 AM PST 09:00 AM PST Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT. December 15, 2018 December 15, 2018 10:00 PM PST 11:00 PM PST Get the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299)
Author 
Message 
TAGS:

Hide Tags

Intern
Joined: 09 Sep 2015
Posts: 4

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
19 Dec 2015, 12:39
Hi Bunnel It might sound lame, but why do we need to consider 2 cases for statement 1? Why can we not simply consider x= zy which means z>y while we are testing for whether y>equal to Z and hence statement 1 is sufficient.



Intern
Status: Pursuit of Happiness
Joined: 10 Sep 2016
Posts: 30
Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 590 Q44 V27 GMAT 2: 690 Q50 V34
GPA: 3.94

Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
20 Oct 2016, 10:29
yashrakhiani wrote: IS x = y z??
1)x+ y = z
2)x<0 Answer is C. From the question, if x>0, x = yz if x<0, x = (yz) = zy Let's start with the easy statement  Statement 2. (2): Insufficient x<0 doesn't give us any information about y and z. Eliminate B and D (1): Insufficient Statement 1 says that x = z  y If x<0 , then the answer is yes since x will be equal to yz if x>0, then the answer is no since x = zy We have a Yes and a No. Eliminate A. (1) and (2) together: Sufficient We have x<0 and x = z  y. hence, x = yz  Need 3 Kudos
_________________
If you find this post hepful, please press +1 Kudos



Intern
Joined: 30 Jun 2016
Posts: 14

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
28 Oct 2016, 22:19
I have a doubt here. if we see, if x is +ve then x=yz and if x is ve x+y = z.
st 1 says x+y = z , so why cant A be suff



Math Expert
Joined: 02 Sep 2009
Posts: 51218

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
28 Oct 2016, 23:41



Intern
Joined: 30 Jun 2016
Posts: 14

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
29 Oct 2016, 00:04
per st 1, when x + y = z, this will happen when x<=0, so this st is sufficient. as when x<=0, then x=yz where am i going wrong or am confusing some concept



Intern
Joined: 21 Dec 2015
Posts: 25
WE: Account Management (Commercial Banking)

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
01 Nov 2016, 07:02
Bunuel : Is mod x = yz I interpreted the question as " Is x = +(yz) or x= (y z)?" And hence, since the first option mentions x = y+z, i chose A. Am i missing something?



Current Student
Status: DONE!
Joined: 05 Sep 2016
Posts: 377

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
01 Nov 2016, 11:36
Tricky, but doable:
(1) x+y = z
Ex 1: 2+3=1 > 31=2 > works *
Ex 2: 3+(2)=1 = > 21=3 > fail (we don't get absolute value)
Ex 3: 3+5=8 > 58=3 > fail
We can see a pattern from Ex 2 and 3 that x must be negative in order for this to work.
NOT SUFFICIENT
(2) x<0 > NOT SUFFICIENT by itself
(1)+(2) > SUFFICIENT



Director
Joined: 26 Oct 2016
Posts: 640
Location: United States
Concentration: Marketing, International Business
GPA: 4
WE: Education (Education)

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
08 Feb 2017, 19:52
EvaJager wrote: sayak636 wrote: Is X= Y Z?
1. X+Y= Z 2. X< 0 (1) Can be rewritten as X = Y + Z, so X = Y + Z, which would be equal to Y  Z, if and only if \(Y+Z\leq0\). Obviously, we don't know that, so (1) insufficient. (2) Cannot be sufficient, it doesn't say anything about Y and Z. (1) and (2) together: X = Y + Z < 0, therefore X = Y  Z, sufficient. Answer: C Hello Eva, Can you please explain how do you reach to below conclusion : "(1) and (2) together: X = Y + Z < 0, therefore X = Y  Z, sufficient."
_________________
Thanks & Regards, Anaira Mitch



VP
Joined: 05 Mar 2015
Posts: 1004

Is x = y  z?
[#permalink]
Show Tags
06 Mar 2017, 18:19
sitagupta385 wrote: Is x = y  z?
1) x + y = z 2) x < 0 is x= yz && x= zy ?? (1) x= zy ...but we dont know whether x= yz.. insuff (2) x<0 so x= zy but we dont know x= yz or not.. insuff combining we know x= yz (from 1) && x= yz(from2) thus x = y  z suff Ans C



Intern
Joined: 03 Jan 2017
Posts: 30

Re: Is x = y  z?
[#permalink]
Show Tags
06 Mar 2017, 19:21
1. X+Y=Z x=yz x=yz Ans a. Hit kudos if i this solution is ryt. Sent from my MotoG3 using GMAT Club Forum mobile app



Manager
Joined: 29 May 2016
Posts: 103

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
07 Mar 2017, 21:56
Bunuel , i have one doubt in this question. i have gone through the explanations in chain, still not clear. suppose we have been asked in question ... is x=1 ? according to explanations it says x=1 && x=1 ? A) x=1 .... so this must be insufficient. please correct me if I am missing anything.



Math Expert
Joined: 02 Sep 2009
Posts: 51218

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
07 Mar 2017, 23:21



Director
Status: Come! Fall in Love with Learning!
Joined: 05 Jan 2017
Posts: 515
Location: India

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
08 Mar 2017, 04:17
St 1: yz = x. if x is positive x = zy. if x is negative, x = yz. INSUFFICIENT St 2: x is negative. no idea about y and z. INSUFFICIENT St 1 & St 2: yz = x. x is negative. hence x = yz. ANSWER Option C
_________________
GMAT Mentors



Manager
Joined: 29 May 2016
Posts: 103

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
08 Mar 2017, 11:26
Bunuel wrote: mbaprep2016 wrote: Bunuel , i have one doubt in this question. i have gone through the explanations in chain, still not clear. suppose we have been asked in question ... is x=1 ? according to explanations it says x=1 && x=1 ? A) x=1 .... so this must be insufficient. please correct me if I am missing anything. So, the question is: Does x = 1? (1) x = 1. This would be sufficient because 1 = 1 and we would have a definite YES answer to the question. Hope it helps. I am sorry for asking same question again and again but with similar logic Question : Is x = y  z? when x > 0 x= yz && when x<0 x= zy ?? we have to choose between two values Now A says x= zy... this clearly indicates x<0 ...hence sufficient



Math Expert
Joined: 02 Sep 2009
Posts: 51218

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
08 Mar 2017, 23:04
mbaprep2016 wrote: Bunuel wrote: mbaprep2016 wrote: Bunuel , i have one doubt in this question. i have gone through the explanations in chain, still not clear. suppose we have been asked in question ... is x=1 ? according to explanations it says x=1 && x=1 ? A) x=1 .... so this must be insufficient. please correct me if I am missing anything. So, the question is: Does x = 1? (1) x = 1. This would be sufficient because 1 = 1 and we would have a definite YES answer to the question. Hope it helps. I am sorry for asking same question again and again but with similar logic Question : Is x = y  z? when x > 0 x= yz && when x<0 x= zy ?? we have to choose between two values Now A says x= zy... this clearly indicates x<0 ...hence sufficient OK. Let me demonstrate with number plugging. For (1) if x = 1, and y =2 and z=3, x does not equal to y  z.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Intern
Joined: 30 Dec 2016
Posts: 14
Location: India
GPA: 3.2

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
25 Apr 2017, 22:09
Hi Bunuel, Please point out the error in my approach. x= y  z. So, when x<0, x=yz => x = z  y(1) x>0, x = y  zStatement 1. x = z  y, which is same as (1). So is A not the answer ?



Manager
Joined: 31 Dec 2016
Posts: 73

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
29 Jul 2017, 17:06
Bunuel wrote: Is \(x=yz\)?
Note that \(yz\) must be \(\geq{0}\), because absolute value (in our case \(x\)) can not be negative.
Generally question asks whether \(yz\geq{0}\) and whether the difference between them equals to \(x\).
(1) \(x=yz\) if \(x>0\) > \(yz\) is negative > no good for us; if \(x\leq{0}\) > \(yz\) is positive > good. Two possible answers not sufficient;
(2) \(x<0\) Not sufficient (we need to know value of yz is equal or not to x)
(1)+(2) Sufficient.
Answer: C. Just to make this good answer a little clearer. An absolute value cannot equal a negative value. Therefore x=yz. as shown in expression 1. If X>0 then we have 5 (because there is a neg sign in front so X = positive 5 but the expression is 5) = yz. But if Yz = 5 that means x = 5 which is not possible! As said above an absolute value has to equal a positive number. So if X<0 then X could be 5 and  * 5 is positive 5. So yz = 5 and therefore together we can say that X=YZ



Manager
Joined: 31 Dec 2016
Posts: 73

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
13 Aug 2017, 17:30
So absolute value we have x = yz or –x = yz . That's how you rewrite the ABS value equation. You write one equation with positive X and one with negative to cover both sides.
1) Tells us X+Y=z . It can be arranged into –x=Yz which matches one of our absolute value formulas. However, if X is positive yz would be negative and then YZ couldn’t equal the absolute value since the ABS value has to equal a non negative numbers.
2) X<0 but we know nothing about Y or Z
3) Combined now we know –(negative number) is positive therefore YZ must be positive = Therefore we know x = y  z ?



Intern
Joined: 09 Mar 2017
Posts: 37

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
31 Aug 2017, 07:54
Bunuel wrote: Is \(x=yz\)?
Note that \(yz\) must be \(\geq{0}\), because absolute value (in our case \(x\)) can not be negative.
Generally question asks whether \(yz\geq{0}\) and whether the difference between them equals to \(x\).
(1) \(x=yz\) if \(x>0\) > \(yz\) is negative > no good for us; if \(x\leq{0}\) > \(yz\) is positive > good. Two possible answers not sufficient;
(2) \(x<0\) Not sufficient (we need to know value of yz is equal or not to x)
(1)+(2) Sufficient.
Answer: C. Bunuel, thanks for your explanation. However, I tried solving this testing cases and I feel like i proved found a case where st1&2 don't hold. Can someone help me out please? 1) x+y=z 2)x<0 Let's say x=4, y=3, z=1 4 +3=1 l4l does not equal 31 (i.e. lxl does not equal yz. However, if you use 2,5,&3 then it does work. Hence, shouldn't it be E?



Math Expert
Joined: 02 Sep 2009
Posts: 51218

Re: Is x = y  z ? (1) x + y = z (2) x < 0
[#permalink]
Show Tags
31 Aug 2017, 07:57
brandon7 wrote: Bunuel wrote: Is \(x=yz\)?
Note that \(yz\) must be \(\geq{0}\), because absolute value (in our case \(x\)) can not be negative.
Generally question asks whether \(yz\geq{0}\) and whether the difference between them equals to \(x\).
(1) \(x=yz\) if \(x>0\) > \(yz\) is negative > no good for us; if \(x\leq{0}\) > \(yz\) is positive > good. Two possible answers not sufficient;
(2) \(x<0\) Not sufficient (we need to know value of yz is equal or not to x)
(1)+(2) Sufficient.
Answer: C. Bunuel, thanks for your explanation. However, I tried solving this testing cases and I feel like i proved found a case where st1&2 don't hold. Can someone help me out please? 1) x+y=z 2)x<0 Let's say x=4, y=3, z=1 4 +3=1l4l does not equal 31 (i.e. lxl does not equal yz. However, if you use 2,5,&3 then it does work. Hence, shouldn't it be E? x=4, y=3, z=1 does not satisfy the first statement.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics




Re: Is x = y  z ? (1) x + y = z (2) x < 0 &nbs
[#permalink]
31 Aug 2017, 07:57



Go to page
Previous
1 2 3
Next
[ 42 posts ]



