Last visit was: 10 Sep 2026, 14:32 It is currently 10 Sep 2026, 14:32
Home
Messages
Tests
Schools
Events
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
User avatar
vrajesh
User avatar
Joined: 25 Jul 2009
Last visit: 25 Nov 2010
Posts: 5
Own Kudos:
56
 [31]
Given Kudos: 2
Posts: 5
Kudos: 56
 [31]
If x - y > 10, is x - y > x + y ? (1) x = 8 (2) y = -20 21 Nov 2010, 16:44
6
Kudos
Add Kudos
25
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

35% (medium)

Question Stats:

69% (01:37) correct 31% (01:40) wrong based on 1082 sessions

History

Date
Time
Result
Not Attempted Yet
If x - y > 10, is x - y > x + y ?

(1) x = 8
(2) y = -20


Show Spoiler
Attachment:
1.JPG
1.JPG [ 48.8 KiB | Viewed 9221 times ]
ShowHide Answer
Official Answer
D
Every tricky question should trigger a follow up quiz. Build that habit with GMAT Club Forum Quiz →.

Pure algebraic questions like this one are no longer part of the GMAT Data Sufficiency syllabus.
For relevant Data Sufficiency questions, please check the Data Sufficiency forum:
Data Sufficiency Forum
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 10 Sep 2026
Posts: 113,419
Own Kudos:
840,525
 [11]
Given Kudos: 111,453
Products:
GMAT Club Tests
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 113,419
Kudos: 840,525
 [11]
If x - y > 10, is x - y > x + y ? (1) x = 8 (2) y = -20 21 Nov 2010, 16:54
8
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
If x - y > 10, is x - y > x + y ?

Given: \(x-y>10\).

Question: is \(x-y>x+y\)?
Is \(2y<0\)?
Is \(y<0\)?

(1) \(x=8\). Plug into \(x - y > 10\):
\(8-y>10\);
\(y<-2\), hence \(y<0\). Sufficient.

(2) \(y=-20\), hence \(y<0\). Sufficient.

Answer: D.
User avatar
jamifahad
User avatar
Joined: 03 Mar 2010
Last visit: 14 Mar 2015
Posts: 256
Own Kudos:
1,783
 [7]
Given Kudos: 22
Schools: Simon '16 (M$)
Schools: Simon '16 (M$)
Posts: 256
Kudos: 1,783
 [7]
If x - y > 10, is x - y > x + y ? (1) x = 8 (2) y = -20 18 Jul 2011, 04:40
7
Kudos
Add Kudos
Bookmarks
Bookmark this Post
siddhans
if x-y > 10 , is x -y > x+ y?

1)x=8

2) y =- 20
Show more

To prove: x-y>x+y
or x-y-x-y>0
or -2y>0
or y<0 ?

Stmt1: x=8
x-y > 10
8-y>10
-2-y>0
2+y<0
y<-2
Hence y < 0. Sufficient.

Stmt2: y=-20
Hence y <0. Sufficient.

OA D.
User avatar
dcummins
User avatar
Joined: 14 Feb 2017
Last visit: 16 Mar 2026
Posts: 1,017
Own Kudos:
2,426
Given Kudos: 368
Location: Australia
Concentration: Technology, Strategy
Schools: INSEAD Sept'21 Intake (WA$$$) Melbourne (A$$$$) AGSM (A$$$$) Kellogg '23 (WL) Said '22 (A$$$$) CBS '23 (D) Booth '23 (WA) Anderson '23 (WA) Cambridge '22 (WL) LBS '23 (D) Stern '24 (WA)
GMAT 1: 560 Q41 V26
GMAT 2: 550 Q43 V23
GMAT 3: 650 Q47 V33
GMAT 4: 650 Q44 V36
GMAT 5: 600 Q38 V35
GMAT 6: 710 Q47 V41
WE:Management Consulting (Consulting)
Products:
My Reviews
Schools: INSEAD Sept'21 Intake (WA$$$) Melbourne (A$$$$) AGSM (A$$$$) Kellogg '23 (WL) Said '22 (A$$$$) CBS '23 (D) Booth '23 (WA) Anderson '23 (WA) Cambridge '22 (WL) LBS '23 (D) Stern '24 (WA)
GMAT 6: 710 Q47 V41
Posts: 1,017
Kudos: 2,426
If x - y > 10, is x - y > x + y ? (1) x = 8 (2) y = -20 07 Oct 2019, 03:11
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If x - y > 10, is x - y > x + y?

Given: \(x-y>10\). Question: is \(x-y>x+y\) --> is \(2y<0\) --> is \(y<0\).

(1) x = 8 --> \(8-y>10\) --> \(y<-2\), hence \(y<0\). Sufficient.
(2) y = -20, hence \(y<0\). Sufficient.

Answer: D.
Show more

So we can do the arithmetic, but we can't divide?
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 10 Sep 2026
Posts: 113,419
Own Kudos:
840,525
Given Kudos: 111,453
Products:
GMAT Club Tests
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 113,419
Kudos: 840,525
If x - y > 10, is x - y > x + y ? (1) x = 8 (2) y = -20 07 Oct 2019, 03:17
Kudos
Add Kudos
Bookmarks
Bookmark this Post
dcummins
Bunuel
If x - y > 10, is x - y > x + y?

Given: \(x-y>10\). Question: is \(x-y>x+y\) --> is \(2y<0\) --> is \(y<0\).

(1) x = 8 --> \(8-y>10\) --> \(y<-2\), hence \(y<0\). Sufficient.
(2) y = -20, hence \(y<0\). Sufficient.

Answer: D.

So we can do the arithmetic, but we can't divide?
Show more

Yes, we can add/subtract a number to both sides of an inequality but we cannot multiply/divide unless we know the sign.
avatar
750Barrier
avatar
Joined: 06 May 2015
Last visit: 21 Sep 2023
Posts: 37
Own Kudos:
3
Given Kudos: 35
GMAT 1: 690 Q48 V37
WE:Consulting (Consulting)
GMAT 1: 690 Q48 V37
Posts: 37
Kudos: 3
If x - y > 10, is x - y > x + y ? (1) x = 8 (2) y = -20 18 Jan 2022, 00:52
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If x - y > 10, is x - y > x + y ?

Given: \(x-y>10\).

Question: is \(x-y>x+y\)?
Is \(2y<0\)?
Is \(y<0\)?

(1) \(x=8\). Plug into \(x - y > 10\):
\(8-y>10\);
\(y<-2\), hence \(y<0\). Sufficient.

(2) \(y=-20\), hence \(y<0\). Sufficient.

Answer: D.
Show more

perfect , no doubt !

but can u pl help me with the following approach? it happened to strike in exam..
lets say i rephrase the question to 'Is X+Y<10 ? ' since i know X-Y>10 .
Now (i) sufficient
but (ii) is not. For example - when I substitute y=-20 in x-y >10 , I get X>-10. and then I use this range in X+Y<10.. i get both Y and N.

need urgent help in this. Thanks Bunuel
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 10 Sep 2026
Posts: 113,419
Own Kudos:
840,525
Given Kudos: 111,453
Products:
GMAT Club Tests
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 113,419
Kudos: 840,525
If x - y > 10, is x - y > x + y ? (1) x = 8 (2) y = -20 18 Jan 2022, 01:40
Kudos
Add Kudos
Bookmarks
Bookmark this Post
750Barrier
Bunuel
If x - y > 10, is x - y > x + y ?

Given: \(x-y>10\).

Question: is \(x-y>x+y\)?
Is \(2y<0\)?
Is \(y<0\)?

(1) \(x=8\). Plug into \(x - y > 10\):
\(8-y>10\);
\(y<-2\), hence \(y<0\). Sufficient.

(2) \(y=-20\), hence \(y<0\). Sufficient.

Answer: D.

perfect , no doubt !

but can u pl help me with the following approach? it happened to strike in exam..
lets say i rephrase the question to 'Is X+Y<10 ? ' since i know X-Y>10 .
Now (i) sufficient
but (ii) is not. For example - when I substitute y=-20 in x-y >10 , I get X>-10. and then I use this range in X+Y<10.. i get both Y and N.

need urgent help in this. Thanks Bunuel
Show more

How did you re-phrased the question as "is x + y < 10?" ? That's not correct. x - y > 10 and y < 0 (actual re-phrased question) can be true even if x + y > 10 is not. For example, x = 100 and y = -1.
avatar
750Barrier
avatar
Joined: 06 May 2015
Last visit: 21 Sep 2023
Posts: 37
Own Kudos:
3
Given Kudos: 35
GMAT 1: 690 Q48 V37
WE:Consulting (Consulting)
GMAT 1: 690 Q48 V37
Posts: 37
Kudos: 3
If x - y > 10, is x - y > x + y ? (1) x = 8 (2) y = -20 18 Jan 2022, 02:37
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
750Barrier
Bunuel
If x - y > 10, is x - y > x + y ?

Given: \(x-y>10\).

Question: is \(x-y>x+y\)?
Is \(2y<0\)?
Is \(y<0\)?

(1) \(x=8\). Plug into \(x - y > 10\):
\(8-y>10\);
\(y<-2\), hence \(y<0\). Sufficient.

(2) \(y=-20\), hence \(y<0\). Sufficient.

Answer: D.

perfect , no doubt !

but can u pl help me with the following approach? it happened to strike in exam..
lets say i rephrase the question to 'Is X+Y<10 ? ' since i know X-Y>10 .
Now (i) sufficient
but (ii) is not. For example - when I substitute y=-20 in x-y >10 , I get X>-10. and then I use this range in X+Y<10.. i get both Y and N.

need urgent help in this. Thanks Bunuel

How did you re-phrased the question as "is x + y < 10?" ? That's not correct. x - y > 10 and y < 0 (actual re-phrased question) can be true even if x + y > 10 is not. For example, x = 100 and y = -1.
Show more

i did the following way.
it's given X-Y> 10 and the question asked is -- is x - y > x + y ? then, i can say Is X+Y<X-Y? since i know X-Y is greater than 10 so, i can say Is X+Y<10? <- rephrased version/ new version of question.

Thank you for taking up my doubt.


aaaaaahh, i got it where my approach was wrong.. Thank you bunuel
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 10 Sep 2026
Posts: 113,419
Own Kudos:
840,525
 [1]
Given Kudos: 111,453
Products:
GMAT Club Tests
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 113,419
Kudos: 840,525
 [1]
If x - y > 10, is x - y > x + y ? (1) x = 8 (2) y = -20 18 Jan 2022, 02:43
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
750Barrier
i did the following way.
it's given X-Y> 10 and the question asked is -- is x - y > x + y ? then, i can say Is X+Y<X-Y? since i know X-Y is greater than 10 so, i can say Is X+Y<10? <- rephrased version/ new version of question.

Thank you for taking up my doubt.


aaaaaahh, i got it where my approach was wrong.. Thank you bunuel
Show more

So, we have that x - y > 10 and the question asks whether x + y < x - y ?

10 < x - y and x + y < x - y does not mean that x + y < 10 < x - y, we could also have that 10 < x + y < x - y.
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 39,213
Own Kudos:
1,158
Posts: 39,213
Kudos: 1,158
If x - y > 10, is x - y > x + y ? (1) x = 8 (2) y = -20 24 Mar 2025, 08:51
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderator:
Bunuel
Math Expert
113419 posts