|
Author |
Message |
|
TAGS:
|
|
|
Intern
Joined: 16 Feb 2012
Posts: 30
GPA: 3.57
Followers: 0
Kudos [?]:
6
[0], given: 0
|
If 5x=y+7, is (x−y)>0 ? [#permalink]
 05 Jun 2012, 20:27
Question Stats:
36% (02:11) correct
63% (00:53) wrong based on 4 sessions
If 5x=y+7, is (x−y)>0 ? (1) xy=6 (2) x and y are consecutive integers with the same sign
|
|
|
|
|
|
|
Senior Manager
Status: mba here i come!
Joined: 07 Aug 2011
Posts: 271
Location: Pakistan
Concentration: Strategy, Marketing
GMAT 1: 680 Q46 V37
GMAT 2: Q V
Followers: 13
Kudos [?]:
458
[1] , given: 48
|
1
This post received
KUDOS
GyanOne wrote: => x = 2 or x= -3/5. So the solutions sets are (x,y) = (2,3) and (-3/5,-10). In both cases, x-y>0. Sufficient. isn't st-1 insufficient because of the above solution set? if (x,y) = (2,3), then x-y=2-3 = -1. a 'no' if (x,y) = (-3/5,-10), then x-y=-3/5+10= 47/5. a 'yes' so, insufficient.
_________________
press +1 Kudos to appreciate posts
Download Valuable Collection of Percentage Questions (PS/DS)
|
|
|
|
|
|
Intern
Joined: 16 Feb 2012
Posts: 30
GPA: 3.57
Followers: 0
Kudos [?]:
6
[0], given: 0
|
Statement 1: xy=6 is not sufficient to answer the question because solving the equation gives y=3 when x is 2 and y is -10 when x is −3 5 .
5x=y+7
x=y+7 5 ................i
xy=6 ........................ ii
Replacing the value of x on eq ii: y(y+7) 5 =6
y 2 +7y=30
y 2 +10y−3y−30=0
y(y+10)−3(y+10)=0
(y+10)(y−3)=0
y=−10 or 3
If y=−10 , x=−3 5 . In this case, x−y=−3 5 −(−10)=47 5 . Yes.
If y=3 , x=2 . In this case, x−y=2−3=−1 . No.
In each case (x−y)>0 and <0 . Hence statement 1 is not sufficient.
Statement 2: If x and y are consecutive integers, x=2 and y=3 .
When x and y are consecutive integers, either x=y+1 or y=x+1 is possible.
(i) If x=y+1
5x=y+7
5(y+1)=y+7
4y=2
y=1 2 . Then x=3 2 . However this is not possible becase x and y are even not integers. So this option is not valid.
(ii) If y=x+1
5x=y+7
5x=x+1+7
4x=8
x=2
Then, y=3 . This is valid because x and y are consecutive integers.
So (x−y)=2−3=−1 . Hence statement 2 is sufficient.
|
|
|
|
|
|
Director
Status:
Joined: 24 Jul 2011
Posts: 504
GMAT 1: 780 Q51 V48
GRE 1: 1540 Q800 V740
Followers: 37
Kudos [?]:
160
[0], given: 9
|
If 5x=y+7 , is (x−y)>0 ? Statement 1: xy=6 => 5x = (6/x) + 7 => 5x^2 - 7x - 6 =0 => (x-2)(5x+3)=0 => x = 2 or x= -3/5. So the solutions sets are (x,y) = (2,3) and (-3/5,-10). In case 1, x-y<0 and in case 2, x-y>0. Insufficient. Statement 2: x and y are consecutive integers with the same sign. Take x=k and y=k+1 => 5k = (k+1) + 7 => k=2. So one possible solution is x=2,y=3. Take y=k and x=k+1 => 5(k+1) = k + 7 => k = 1/2. So no solution possible in integers. Therefore x-y<0. Sufficient. The answer is B.
_________________
Free profile evaluation by top b-school alumni: email us at info@gyanone.com
B-school application service http://www.gyanone.com/appone.html
[b]Visit our blog: www.gyanone.com/blog
Last edited by GyanOne on 06 Jun 2012, 17:44, edited 1 time in total.
|
|
|
|
|
|
Director
Status: Gonna rock this time!!!
Joined: 22 Jul 2012
Posts: 551
Location: India
GMAT 1: 640 Q43 V34
GMAT 2: 630 Q47 V29
WE: Information Technology (Computer Software)
Followers: 1
Kudos [?]:
13
[0], given: 560
|
Re: If 5x=y+7, is (x−y)>0 ? [#permalink]
19 Feb 2013, 08:00
Bunuel, x and y are consecutive integers with the same signDoesn't the above indicate that y is bigger than x by 1?
_________________
hope is a good thing, maybe the best of things. And no good thing ever dies.
Who says you need a 700 ?Check this out : http://gmatclub.com/forum/who-says-you-need-a-149706.html#p1201595
My GMAT Journey : end-of-my-gmat-journey-149328.html#p1198742
|
|
|
|
|
|
GMAT Club team member
Joined: 02 Sep 2009
Posts: 11565
Followers: 1796
Kudos [?]:
9570
[0], given: 826
|
Re: If 5x=y+7, is (x−y)>0 ? [#permalink]
19 Feb 2013, 08:28
|
|
|
|
|
|
Director
Status: Gonna rock this time!!!
Joined: 22 Jul 2012
Posts: 551
Location: India
GMAT 1: 640 Q43 V34
GMAT 2: 630 Q47 V29
WE: Information Technology (Computer Software)
Followers: 1
Kudos [?]:
13
[0], given: 560
|
Re: If 5x=y+7, is (x−y)>0 ? [#permalink]
19 Feb 2013, 08:55
Bunuel wrote: Sachin9 wrote: Bunuel,
x and y are consecutive integers with the same sign
Doesn't the above indicate that y is bigger than x by 1? No, it dose not. When we are told that x and y are consecutive integers, it doesn't necessarily mean that y=x+1 (y>x), it could be that x=y+1 (x>y). For example, check the following question: if-m-and-n-are-consecutive-positive-integers-is-m-greater-126287.html#p1031359Hope it helps. Bunuel, I checked The link you gave . There m has to be greater than n. But here in this question, it is given that x and y are consecutive. Meaning of consecutive from google indicates that y follows x.. con·sec·u·tive
/kənˈsekyətiv/
Adjective
Following continuously.
In unbroken or logical sequence.
Synonyms
successive - sequential - running - sequent - serialSo y has to be bigger than x right?
_________________
hope is a good thing, maybe the best of things. And no good thing ever dies.
Who says you need a 700 ?Check this out : http://gmatclub.com/forum/who-says-you-need-a-149706.html#p1201595
My GMAT Journey : end-of-my-gmat-journey-149328.html#p1198742
|
|
|
|
|
|
GMAT Club team member
Joined: 02 Sep 2009
Posts: 11565
Followers: 1796
Kudos [?]:
9570
[0], given: 826
|
Re: If 5x=y+7, is (x−y)>0 ? [#permalink]
19 Feb 2013, 08:59
Sachin9 wrote: Bunuel wrote: Sachin9 wrote: Bunuel,
x and y are consecutive integers with the same sign
Doesn't the above indicate that y is bigger than x by 1? No, it dose not. When we are told that x and y are consecutive integers, it doesn't necessarily mean that y=x+1 (y>x), it could be that x=y+1 (x>y). For example, check the following question: if-m-and-n-are-consecutive-positive-integers-is-m-greater-126287.html#p1031359Hope it helps. Bunuel, I checked The link you gave . There m has to be greater than n. But here in this question, it is given that x and y are consecutive. Meaning of consecutive from google indicates that y follows x.. con·sec·u·tive
/kənˈsekyətiv/
Adjective
Following continuously.
In unbroken or logical sequence.
Synonyms
successive - sequential - running - sequent - serialSo y has to be bigger than x right? Google is not conducting the test, GMAC does.
_________________
PLEASE READ AND FOLLOW: 11 Rules for Posting!!!
RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory
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. NEW!!!
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. NEW!!!
What are GMAT Club Tests?
25 extra-hard Quant Tests
Find out what's new at GMAT Club - latest features and updates
|
|
|
|
|
|
Director
Status: Gonna rock this time!!!
Joined: 22 Jul 2012
Posts: 551
Location: India
GMAT 1: 640 Q43 V34
GMAT 2: 630 Q47 V29
WE: Information Technology (Computer Software)
Followers: 1
Kudos [?]:
13
[0], given: 560
|
Re: If 5x=y+7, is (x−y)>0 ? [#permalink]
19 Feb 2013, 09:44
lol 
_________________
hope is a good thing, maybe the best of things. And no good thing ever dies.
Who says you need a 700 ?Check this out : http://gmatclub.com/forum/who-says-you-need-a-149706.html#p1201595
My GMAT Journey : end-of-my-gmat-journey-149328.html#p1198742
|
|
|
|
|
|
|
Re: If 5x=y+7, is (x−y)>0 ?
[#permalink]
19 Feb 2013, 09:44
|
|
|
|
|
|
|
|
|
|
|
close
