Last visit was: 15 Dec 2024, 08:39 It is currently 15 Dec 2024, 08:39
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
User avatar
chetan2u
User avatar
RC & DI Moderator
Joined: 02 Aug 2009
Last visit: 14 Dec 2024
Posts: 11,433
Own Kudos:
38,064
 []
Given Kudos: 333
Status:Math and DI Expert
Products:
Expert reply
Posts: 11,433
Kudos: 38,064
 []
1
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
User avatar
susheelh
Joined: 12 Jun 2016
Last visit: 13 Jun 2018
Posts: 144
Own Kudos:
Given Kudos: 151
Location: India
Concentration: Technology, Leadership
WE:Sales (Telecommunications)
Posts: 144
Kudos: 249
Kudos
Add Kudos
Bookmarks
Bookmark this Post
avatar
Bang2919
Joined: 23 Aug 2015
Last visit: 02 Mar 2018
Posts: 22
Own Kudos:
Given Kudos: 459
Location: India
Concentration: General Management, Human Resources
GMAT 1: 610 Q46 V29
GPA: 3
WE:Consulting (Human Resources)
GMAT 1: 610 Q46 V29
Posts: 22
Kudos: 6
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
chetan2u
User avatar
RC & DI Moderator
Joined: 02 Aug 2009
Last visit: 14 Dec 2024
Posts: 11,433
Own Kudos:
38,064
 []
Given Kudos: 333
Status:Math and DI Expert
Products:
Expert reply
Posts: 11,433
Kudos: 38,064
 []
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bang2919
chetan2u
If a and b are integers and a*b=2, is a>b?

(1) \(\frac{a}{b}>1\)
(2) \(a^2>b^2\)

self made

By using numbers we can arrive at E but I have a doubt in using algebra.

Since a*b=2, both a and b has to be same sign.

St.1: \(\frac{a}{b}>1\)

If a and b are positive, we can conclude a>b.
If a and b are negative, \(\frac{-a}{-b}\), will those signs not cancel out and become just a/b ? Should we invert > sign even when we cancel sign in numerator and denominator?

Please advise.


Hi..
When a and b are NEGATIVE, it does not become -a/-b, it remains a/b because NEGATIVE sign is within a and b..

So a =-x, b =-y...
Now -x/-y>1....X>y.... Substitute in terms of a and B..
-a>-b.....Multiply by -1 and invert sign..
a<b..

Or a/b>1... \(1-\frac{a}{b}<0......\frac{b-a}{b}<0.....\)
So b-a and b will be of different sign..
b is NEGATIVE, so b-a>0...b>a

Follow any of above..
User avatar
stonecold
Joined: 12 Aug 2015
Last visit: 09 Apr 2024
Posts: 2,261
Own Kudos:
Given Kudos: 893
GRE 1: Q169 V154
GRE 1: Q169 V154
Posts: 2,261
Kudos: 3,302
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Great question.
Here is what I did on this one -->


Since a and b are integers => a*b=2 => The possible cases are ==>
1,2
2,1
-1,-2
-2,-1


Lets see the 2 statements =>
a/b>1
Hence the two possible pairs are =>
(2,1)=> YES a>b is true
(-2,-1)=> NO a>b is false.

Hence not sufficient.

Statement 2 =>
a^2>b^2

Again => the two possible pairs are =>
(2,1)=> YES a>b is true
(-2,-1)=> NO a>b is false.


Not sufficient.

Combining the two statements => Two possible pairs are =>
(2,1)=> YES a>b is true
(-2,-1)=> NO a>b is false.

Hence not sufficient.

Hence E.
Moderator:
Math Expert
97883 posts