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

 It is currently 17 Feb 2019, 18:29

### 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

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

## Events & Promotions

###### Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
• ### Free GMAT Algebra Webinar

February 17, 2019

February 17, 2019

07:00 AM PST

09:00 AM PST

Attend this Free Algebra Webinar and learn how to master Inequalities and Absolute Value problems on GMAT.
• ### Valentine's day SALE is on! 25% off.

February 18, 2019

February 18, 2019

10:00 PM PST

11:00 PM PST

We don’t care what your relationship status this year - we love you just the way you are. AND we want you to crush the GMAT!

# Veritas Prep 10 Year Anniversary Promo Question #5

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 52906
Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:00
1
4
00:00

Difficulty:

35% (medium)

Question Stats:

60% (01:09) correct 40% (00:48) wrong based on 165 sessions

### HideShow timer Statistics

Veritas Prep 10 Year Anniversary Promo Question #5

One quant and one verbal question will be posted each day starting on Monday Sept 17th at 10 AM PST/1 PM EST and the first person to correctly answer the question and show how they arrived at the answer will win a free Veritas Prep GMAT course (\$1,650 value). Winners will be selected and notified by a GMAT Club moderator. For more questions and details please check here: veritas-prep-10-year-anniversary-giveaway-138806.html

To participate, please make sure you provide the correct answer (A,B,C,D,E) and explanation that clearly shows how you arrived at it.
Winners will be announced the following day at 10 AM Pacific/1 PM Eastern Time.

What is the value of integer $$q$$?

(1) $$qr + qs = r + s$$
(2) $$r\neq{-s}$$

_________________
Math Expert
Joined: 02 Sep 2009
Posts: 52906
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:00

Winner:

Vips0000

Official Explanation:

Statement 1 at first appears to be sufficient, as one can factor out the common $$q$$ to get: $$q(r + s) = r + s$$. This would suggest that $$q$$ equals one. But you must ask about statement 2, “why are you here?”. Statement 2 is clearly not sufficient, but it sheds a bit of light on something you may not have considered with statement 1. If $$r$$ were to equal $$-{s}$$, then $$r + s$$ would be 0. And in that case, our revised equation for statement 1, $$q(r + s) = r + s$$, is true for any value of $$q$$. So statement 2 is critical - it shows us that statement 1 is not sufficient alone, but that along with statement 2 we can rest assured that $$q$$ is 1. The correct answer is C.
_________________
Director
Status: Done with formalities.. and back..
Joined: 15 Sep 2012
Posts: 587
Location: India
Concentration: Strategy, General Management
Schools: Olin - Wash U - Class of 2015
WE: Information Technology (Computer Software)
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:01
Ans is C

A gives us either q=1 or r=-s.. but can not say
B gives us r not equal to -s..

Combining we get q=1
So C
_________________

Lets Kudos!!!
Black Friday Debrief

Senior Manager
Joined: 24 Aug 2009
Posts: 467
Schools: Harvard, Columbia, Stern, Booth, LSB,
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:03
1) insufficient as q can be 1 or 0
2) Insufficient
3) Q = is 1 as r is not equal to - s
_________________

If you like my Question/Explanation or the contribution, Kindly appreciate by pressing KUDOS.
Kudos always maximizes GMATCLUB worth
-Game Theory

If you have any question regarding my post, kindly pm me or else I won't be able to reply

Manager
Status: faciendo quod indiget fieri
Joined: 13 Mar 2012
Posts: 71
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:04
ans is c

because we need b otherwise we cant cancel 0 on both sides
Manager
Status: faciendo quod indiget fieri
Joined: 13 Mar 2012
Posts: 71
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:05
@ mods..i just could not see the question before 10:03..i tried refreshing but it was linking to question number 3 !
Intern
Joined: 31 Oct 2011
Posts: 33
Concentration: General Management, Entrepreneurship
GMAT 1: 710 Q50 V35
GPA: 3.4
WE: Accounting (Commercial Banking)
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:09
(1) qr + qs = r + s <=> q (r+s) = (r+s) <=> r + s = 0 or q = 1
Can't determine q -> not sufficient
(2) r is different to -s => r+s <> 0 . No information about q -> not sufficient

(1) + (2): r+s <> 0 & q(r+s) = (r+s) => q =1
Sufficient

Intern
Joined: 03 Jul 2012
Posts: 5
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:09
Solution:
What is the value of integer ?

We have: (1) qr+qs = r+s
Then q(r+s) = r+s => (q-1)(r+s)=0 => q=1 or r=-s. So it’s not Sufficient
Together with (2) r≠-s, we have q=1.So the answer is C
Intern
Joined: 31 Mar 2011
Posts: 5
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:16
Ans is C.
stmt 1) qr + qs = r + s => q(r+s) = (r+s)
=> q=1 if (r+s) not equal to 0 OR q does not have unique value if (r+s)=0
stmt 2) r not equal to -s => (r+s) not equal to 0
Hence, to find unique value of q stmt 1) & 2) both necessary
Intern
Joined: 14 Feb 2012
Posts: 45
Location: United States
WE: Project Management (Consulting)
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:38

Statement 1:
qr + qs = r + s
q(r + s) = r + s

most of the people prefer to divide both sides by (r + S) and hence conclude that q = 1. As per my understanding, GMAT does not prefer that way because it eliminates one solution. (if one does as this, one will miss (r + s) = 0 as answer)

As per my understanding,
q(r + s) = r + s
q(r + s) - (r + s) = 0
(r + s)(q - 1) = 0

either (r + s) = 0 or (q - 1) = 0. if (r + s) = 0 then q can have any value.
statement 1 insufficient.

Statement 2:
r is not equal to -s does not provide any information about value of q
statement 2 is insufficient.

statement 1 and 2:
from statement 1, we know that either (r + s) = 0 or (q - 1) = 0
but from statement 2, we know that r NE -s, so (r + s) NE 0

substitute this in statemet 1. we will get (q - 1) = 0

q = 1

sufficient

Intern
Joined: 20 May 2012
Posts: 16
Concentration: Entrepreneurship, Strategy
GMAT 1: 690 Q47 V37
WE: Engineering (Manufacturing)
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 09:46
Ans : C
R+c should not be 0 in the 1st equation to get a value for Q
This is confirmed by 2nd statement. " R+c not= 0"
We need both statements together so ans is C
Intern
Joined: 27 Oct 2011
Posts: 2
Concentration: Entrepreneurship, Finance
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 10:41
C.
- (2) is not sufficient since irrelevant. BD out
- (1) q (r+s) = r + s
(q-1)(r+s)= 0
=> Either (q-1) = 0 or (r+s) = 0. Not sufficient in case of (r+s) = 0. A out
- Both (1)&(2), from (2) we have r+s <>0, combine with (1) we have q = 1: sufficient
Manager
Joined: 16 Feb 2011
Posts: 176
Schools: ABCD
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 16:50
C
a - if r+s = 0; q could be anything
B - not sufficient
C- works. Q=1
Senior Manager
Status: Final Countdown
Joined: 17 Mar 2010
Posts: 431
Location: United States (NY)
GPA: 3.82
WE: Account Management (Retail Banking)
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 19:18
why not (A)?
(i)q(r+s)=(r+s)
q=? ...(doesn't matter what r or s is , we have to find the q ;not to check whether is positive negative or zero);the value cant be found out insufficient so (A) is
sufficient
(ii) lacks info-insufficient
_________________

" Make more efforts "
Press Kudos if you liked my post

Intern
Joined: 15 Oct 2011
Posts: 31
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

Updated on: 19 Sep 2012, 19:51
1) qr + qs = r + s thus, q (r+s) = (r+s). Now you can't divide since r+s=0. If r+s is not 0, then q=1. Hence insufficient
2) r+s is not = 0. no information about q.

Both combined - we can say that q = 1.

Originally posted by prep on 19 Sep 2012, 19:48.
Last edited by prep on 19 Sep 2012, 19:51, edited 1 time in total.
Senior Manager
Joined: 13 Aug 2012
Posts: 420
Concentration: Marketing, Finance
GPA: 3.23
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 20:09
thevenus wrote:
why not (A)?
(i)q(r+s)=(r+s)
q=? ...(doesn't matter what r or s is , we have to find the q ;not to check whether is positive negative or zero);the value cant be found out insufficient so (A) is
sufficient
(ii) lacks info-insufficient

A will only be the answer if statement (1) is sufficient to provide one exact answer to the question, what is the value of q?
_________________

Impossible is nothing to God.

Manager
Joined: 31 Mar 2010
Posts: 104
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 21:14
A.

q(R+S) =(R+S)

Let the value of r and s be anything q will always be equal to 1.
_________________

Push +1 kudos button please, if you like my post

Director
Status: Done with formalities.. and back..
Joined: 15 Sep 2012
Posts: 587
Location: India
Concentration: Strategy, General Management
Schools: Olin - Wash U - Class of 2015
WE: Information Technology (Computer Software)
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 21:29
yashii9 wrote:
A.

q(R+S) =(R+S)

Let the value of r and s be anything q will always be equal to 1.

Not correct approach.
what if R=S=0 then?
Q(R+S) = 1*(R+S) => Q=1 ?
as well as Q(R+S)=10*(R+S) =>Q=10 ?
and it can be shown to be true for any other number... So first you can not claim Q=1 this way.
Second, the conclusion u reached
Q(R+S) =(R+S) => Q=1
this is arrived when you've divided both sides by (R+S). Which can not be done if R+S = 0, as it will be illegal operation to divide by 0. Unless you are certain about r+s <>0, you can not reach to conclusion.
_________________

Lets Kudos!!!
Black Friday Debrief

Manager
Joined: 31 Mar 2010
Posts: 104
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

19 Sep 2012, 21:33
Vips0000 wrote:
yashii9 wrote:
A.

q(R+S) =(R+S)

Let the value of r and s be anything q will always be equal to 1.

Not correct approach.
what if R=S=0 then?
Q(R+S) = 1*(R+S) => Q=1 ?
as well as Q(R+S)=10*(R+S) =>Q=10 ?
and it can be shown to be true for any other number... So first you can not claim Q=1 this way.
Second, the conclusion u reached
Q(R+S) =(R+S) => Q=1
this is arrived when you've divided both sides by (R+S). Which can not be done if R+S = 0, as it will be illegal operation to divide by 0. Unless you are certain about r+s <>0, you can not reach to conclusion.

Dear vips - if r or s is 0... the equation will be 0 on both side..and u can not get the value of q.

if either r or s is 0 u still get q=1
isnt it?

Also if we are to consider this as an unanswerable case - then even point 2 wont help. r not equal to -s...could well mean r =s =0 again no answer and then reach the conclusion to be E.

What do you say?
_________________

Push +1 kudos button please, if you like my post

Intern
Status: gmat fresher
Joined: 07 Jun 2012
Posts: 24
GPA: 3.87
Re: Veritas Prep 10 Year Anniversary Promo Question #5  [#permalink]

### Show Tags

Updated on: 19 Sep 2012, 23:24
1
Ans:C
Statement1:given qr+qs=r+s
=>q(r+s)=r+s
=>q=1 only when r not equal to -s
If r=-s,then q is undefined
Hence Statement1 is insufficient
Statement2:given r not equal to -s
Hence Statement2 is insufficient

By combining both statements 1 and 2
q=1 when r not equal to -s
Hence C is the correct answer

Originally posted by sdpp143 on 19 Sep 2012, 23:15.
Last edited by sdpp143 on 19 Sep 2012, 23:24, edited 1 time in total.
Re: Veritas Prep 10 Year Anniversary Promo Question #5   [#permalink] 19 Sep 2012, 23:15

Go to page    1   2    Next  [ 28 posts ]

Display posts from previous: Sort by