GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 15 Jul 2018, 16:22

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

If a and b are integers and a*b=2, is a>b?

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

Hide Tags

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 6196
If a and b are integers and a*b=2, is a>b? [#permalink]

Show Tags

New post 15 Jul 2017, 21:54
1
2
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

57% (01:03) correct 43% (00:59) wrong based on 66 sessions

HideShow timer Statistics

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

_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

Manager
Manager
avatar
G
Joined: 12 Jun 2016
Posts: 221
Location: India
Concentration: Technology, Leadership
WE: Sales (Telecommunications)
GMAT ToolKit User
Re: If a and b are integers and a*b=2, is a>b? [#permalink]

Show Tags

New post 16 Jul 2017, 00:18
IMO the answer is
E.


Stem : a and b and integers and their product is 2. Possible values of a,b = (2,1) or (1,2) or (-2,-1) or (-1, -2)
Needed: Is a > b?

I found it easier to keep track of the possibilities by using a table and Working through S1, S2 and S1+S2. Table is attached.

From the Table we can see

S1 : a and b could be (2,1) or (-2,-1). So a > b or a < b. Insuff

S2: \(a^2 > b^2 => a^2-b^2 > 0\).

a and b could be (2,1) or (-2,-1). So a > b or a < b. Insuff

S1+S2: a and b could still be (2,1) or (-2,-1). So a > b or a < b. Insuff

Even with both statements its not suff.

I hope I am correct
Attachments

Quant question by Chetan2u.png
Quant question by Chetan2u.png [ 14.8 KiB | Viewed 679 times ]


_________________

My Best is yet to come!

Intern
Intern
avatar
B
Joined: 23 Aug 2015
Posts: 24
Location: India
Concentration: General Management, Human Resources
GMAT 1: 610 Q46 V29
GPA: 3
WE: Consulting (Human Resources)
If a and b are integers and a*b=2, is a>b? [#permalink]

Show Tags

New post 14 Aug 2017, 03:52
chetan2u wrote:
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.
Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 6196
Re: If a and b are integers and a*b=2, is a>b? [#permalink]

Show Tags

New post 14 Aug 2017, 04:23
1
Bang2919 wrote:
chetan2u wrote:
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..
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

BSchool Forum Moderator
User avatar
D
Joined: 12 Aug 2015
Posts: 2646
GRE 1: 323 Q169 V154
GMAT ToolKit User Premium Member
Re: If a and b are integers and a*b=2, is a>b? [#permalink]

Show Tags

New post 14 Aug 2017, 04:54
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.

_________________


MBA Financing:- INDIAN PUBLIC BANKS vs PRODIGY FINANCE!

Getting into HOLLYWOOD with an MBA!

The MOST AFFORDABLE MBA programs!

STONECOLD's BRUTAL Mock Tests for GMAT-Quant(700+)

AVERAGE GRE Scores At The Top Business Schools!

Re: If a and b are integers and a*b=2, is a>b?   [#permalink] 14 Aug 2017, 04:54
Display posts from previous: Sort by

If a and b are integers and a*b=2, is a>b?

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

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.