It is currently 17 Feb 2018, 17:08

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Is xm < ym ?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Top Contributor
2 KUDOS received
Board of Directors
User avatar
G
Joined: 01 Sep 2010
Posts: 3472
Is xm < ym ? [#permalink]

Show Tags

New post 26 Jul 2017, 08:10
2
This post received
KUDOS
Top Contributor
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

67% (00:38) correct 33% (00:45) wrong based on 212 sessions

HideShow timer Statistics

Expert Post
3 KUDOS received
GMAT Tutor
avatar
S
Joined: 24 Jun 2008
Posts: 1346
Re: Is xm < ym ? [#permalink]

Show Tags

New post 26 Jul 2017, 08:20
3
This post received
KUDOS
Expert's post
Using both statements, if we take the inequality in Statement 1:

x > y

and multiply by m on both sides, we need to reverse the inequality, because, as Statement 2 tells us, m < 0. So we get

xm < ym

which is what we wanted. Statement 1 is not sufficient alone because we need to know if m is positive or negative, and Statement 2 is not sufficient alone since we have no information about x or y. So the answer is C.
_________________

GMAT Tutor in Toronto

If you are looking for online GMAT math tutoring, or if you are interested in buying my advanced Quant books and problem sets, please contact me at ianstewartgmat at gmail.com

1 KUDOS received
Manager
Manager
avatar
B
Joined: 29 Jun 2017
Posts: 241
Re: Is xm < ym ? [#permalink]

Show Tags

New post 03 Aug 2017, 08:06
1
This post received
KUDOS
2
This post was
BOOKMARKED
carcass wrote:
Is \(xm < ym\) ?

(1) \(x > y\)

(2) \(m < 0\)


this is more simple method

xm<ym
move ym to the left
xm-ym<0
m(x-y)<0

now we can analyse , applying case 1 and 2.
Intern
Intern
avatar
B
Joined: 23 Apr 2017
Posts: 3
Re: Is xm < ym ? [#permalink]

Show Tags

New post 13 Aug 2017, 02:29
Hi,

m(x-y)<0 -- > m<0 or x>y
do we need 2 conditions together or each condition alone is suff??

as it is m<0 OR x>y can we not select D as the answer?
please clarify.

Thanks. :)
Expert Post
Top Contributor
2 KUDOS received
SVP
SVP
User avatar
P
Joined: 11 Sep 2015
Posts: 2049
Location: Canada
Re: Is xm < ym ? [#permalink]

Show Tags

New post 13 Aug 2017, 07:42
2
This post received
KUDOS
Expert's post
Top Contributor
carcass wrote:
Is \(xm < ym\) ?

(1) \(x > y\)

(2) \(m < 0\)


Target question: Is xm < ym?
Another approach is to rephrase the target question.

Take the inequality and subtract ym from both sides to get: xm - ym < 0
Factor out the m to get m(x - y) < 0
In other words....
REPHRASED target question: Is m(x - y) a NEGATIVE value?

Statement 1: x > y
Subtract y from both sides to get: x - y > 0
So, x - y is a POSITIVE value
Does this provide enough information to determine whether or not m(x - y) a NEGATIVE value?
No. We still don't know anything about the value of m
Since we cannot answer the REPHRASED target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: m < 0
In other words, m is NEGATIVE
Does this provide enough information to determine whether or not m(x - y) a NEGATIVE value?
No. We don't know anything about the value of (x - y)
Since we cannot answer the REPHRASED target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Statement 1 tells us that x - y is a POSITIVE value
Statement 2 tells us that m is a NEGATIVE value
So, m(x - y) = (NEGATIVE)(POSITIVE) = some NEGATIVE VALUE
In other words, m(x - y) is definitely a NEGATIVE value
Since we can answer the REPHRASED target question with certainty, the combined statements are SUFFICIENT

Answer:
[Reveal] Spoiler:
C


RELATED VIDEO FROM OUR COURSE

_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Re: Is xm < ym ?   [#permalink] 13 Aug 2017, 07:42
Display posts from previous: Sort by

Is xm < ym ?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.