Find all School-related info fast with the new School-Specific MBA Forum

It is currently 01 Oct 2014, 18:23

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

M02 Q31 (DS)

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 09 Jun 2008
Posts: 24
Schools: Kellogg
Followers: 0

Kudos [?]: 8 [0], given: 2

M02 Q31 (DS) [#permalink] New post 14 Feb 2009, 23:15
1
This post was
BOOKMARKED
If x and y represent digits of a two digit number divisible by 3, is the two digit number less than 50?

1. Sum of the digits is a multiple of 18
2. Product of the digits is a multiple of 9

[Reveal] Spoiler: OA
A

Source: GMAT Club Tests - hardest GMAT questions

I answered E (Statements 1+2 together are not sufficient), thinking that the number could be either 99 or -99. The answer says A (statement 1 is sufficient), because the only solution can be 99.

Is the answer wrong or am I missing something? What about -99?
Kaplan Promo CodeKnewton GMAT Discount CodesVeritas Prep GMAT Discount Codes
3 KUDOS received
Intern
Intern
avatar
Joined: 09 Jun 2008
Posts: 24
Schools: Kellogg
Followers: 0

Kudos [?]: 8 [3] , given: 2

Re: M02 Q31 (DS) [#permalink] New post 15 Feb 2009, 12:00
3
This post received
KUDOS
GMAT TIGER,
I agree with you. First of all, the number -99 is a negative integer with 2 digits (9 and 9). A digit is an integer from 0 to 9. There is no "negative digit", so we can't have a digit equal to -9.

So, from what I understand, the GMATclub answer to that question is wrong, right? It should be E instead of A.

(Indeed, even for the case of -9 and 9, the sum is 0, which i a multiple of 18, as 18*0=0.. but that's not part of this solution).
3 KUDOS received
Manager
Manager
User avatar
Joined: 14 Aug 2009
Posts: 123
Followers: 2

Kudos [?]: 90 [3] , given: 13

Re: M02 Q31 (DS) [#permalink] New post 23 Aug 2009, 22:01
3
This post received
KUDOS
river wrote:
If x and y represent digits of a two digit number divisible by 3, is the two digit number less than 50?
1. Sum of the digits is a multiple of 18
2. Product of the digits is a multiple of 9

I answered E (Statements 1+2 together are not sufficient), thinking that the number could be either 99 or -99. The answer says A (statement 1 is sufficient), because the only solution can be 99.

Is the answer wrong or am I missing something? What about -99?


Answer is A.

for 1), "Sum of the digits is a multiple of 18" tells that x=y=9 only, and 99 is divisible by 3. But it >50
it is a "No, but sufficient to tell No" question.

for 2), "Product of the digits is a multiple of 9" and with "a two digit number divisible by 3" xy can be 63 or 36, insuf.

So the answer is A for sure.
_________________

Kudos me if my reply helps!

2 KUDOS received
Manager
Manager
avatar
Joined: 17 May 2010
Posts: 122
Location: United States
Concentration: Entrepreneurship, Marketing
Schools: USC (Marshall) - Class of 2013
GMAT 1: 770 Q50 V46
GPA: 3.26
WE: Brand Management (Consumer Products)
Followers: 6

Kudos [?]: 28 [2] , given: 5

Re: M02 Q31 (DS) [#permalink] New post 27 Sep 2010, 14:49
2
This post received
KUDOS
imo no higher than 600-700 level. Not a difficult question.

As discussed above a "digit" cannot be negative, i.e. -3541—who can tell which digit is negative? Is it the 3 or the 1? Illogical point. So the only way a two-digit number can have its digits add up to 18 is if they were 9 and 9, hence 99 > 50. For (2) 3*3 can total 9, a multiple of 3, or 6*6 can total 36, which is also a multiple of 3, but > 50. A it is.
_________________

Discipline + Hard Work = Success! 770 (Q50, V46)

1 KUDOS received
Manager
Manager
User avatar
Joined: 10 Jan 2009
Posts: 111
Followers: 11

Kudos [?]: 142 [1] , given: 0

Re: M02 Q31 (DS) [#permalink] New post 15 Feb 2009, 04:30
1
This post received
KUDOS
Hi river,


If you consider -99, then what are the values of x & y?

It can only be (-9 & 9) OR (9 & -9) respectively. In either case, you get their sum as 0, which is not a multiple of 18. So, it doesn't satisfy option 1.

Does it make sense? HTH.


Regards,
Technext
_________________

+++ Believe me, it doesn't take much of an effort to underline SC questions. Just try it out. +++
+++ Please tell me why other options are wrong. +++

~~~ The only way to get smarter is to play a smarter opponent. ~~~

1 KUDOS received
CEO
CEO
User avatar
Joined: 29 Aug 2007
Posts: 2501
Followers: 53

Kudos [?]: 508 [1] , given: 19

Re: M02 Q31 (DS) [#permalink] New post 15 Feb 2009, 08:03
1
This post received
KUDOS
Technext wrote:
Hi river,


If you consider -99, then what are the values of x & y?

It can only be (-9 & 9) OR (9 & -9) respectively. In either case, you get their sum as 0, which is not a multiple of 18. So, it doesn't satisfy option 1.

Does it make sense? HTH.


Regards,
Technext


0 is a multiple of any numer or integer. Even if the integer is 99 or -99, the sum is a multiple of 18. However it is confusing about to how to assign the value of x and y if the integer is -99.

So A is insuff...

river wrote:
If x and y represent digits of a two digit number divisible by 3, is the two digit number less than 50?
1. Sum of the digits is a multiple of 18
2. Product of the digits is a multiple of 9

I answered E (Statements 1+2 together are not sufficient), thinking that the number could be either 99 or -99. The answer says A (statement 1 is sufficient), because the only solution can be 99.

Is the answer wrong or am I missing something? What about -99?

_________________

Verbal: new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html


GT

1 KUDOS received
Manager
Manager
User avatar
Joined: 10 Jan 2009
Posts: 111
Followers: 11

Kudos [?]: 142 [1] , given: 0

Re: M02 Q31 (DS) [#permalink] New post 15 Feb 2009, 09:24
1
This post received
KUDOS
Hi GMAT TIGER,


Thanks for clarifying this; I actually came across this fact just few months back only but it just skipped. Thanks again.

Although you've quoted that the problem is confusing, at last you've mentioned in your reply that 'So A is suff...'. If 99 & -99 both satisfy option 1, then how can we conclude that A is sufficient? Do you agree with A as the right answer?


Regards,
Technext
_________________

+++ Believe me, it doesn't take much of an effort to underline SC questions. Just try it out. +++
+++ Please tell me why other options are wrong. +++

~~~ The only way to get smarter is to play a smarter opponent. ~~~

1 KUDOS received
CEO
CEO
User avatar
Joined: 29 Aug 2007
Posts: 2501
Followers: 53

Kudos [?]: 508 [1] , given: 19

Re: M02 Q31 (DS) [#permalink] New post 15 Feb 2009, 10:16
1
This post received
KUDOS
Technext wrote:
Hi GMAT TIGER,


Thanks for clarifying this; I actually came across this fact just few months back only but it just skipped. Thanks again.

Although you've quoted that the problem is confusing, at last you've mentioned in your reply that 'So A is suff...'. If 99 & -99 both satisfy option 1, then how can we conclude that A is sufficient? Do you agree with A as the right answer?


Regards,
Technext


Thats typo. A is insuff.
Thanks.
_________________

Verbal: new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html


GT

1 KUDOS received
Senior Manager
Senior Manager
avatar
Joined: 27 May 2009
Posts: 282
Followers: 2

Kudos [?]: 66 [1] , given: 18

Re: M02 Q31 (DS) [#permalink] New post 29 Aug 2009, 02:36
1
This post received
KUDOS
there is no way we can take a single digit of a two digit no as a negative.....not possible..its clearly A
1 KUDOS received
Intern
Intern
avatar
Joined: 04 Sep 2009
Posts: 7
Followers: 0

Kudos [?]: 1 [1] , given: 0

Re: M02 Q31 (DS) [#permalink] New post 28 Sep 2010, 17:48
1
This post received
KUDOS
A. 0 is not a universal multiple. The negative in a negative number cannot be assigned to a digit of the number; it's a property of the entire number, not of a digit i.e. -(99) != (-9)(9) or (9)(-9).
Thanks for the post.

Last edited by rkurra on 28 Sep 2010, 18:40, edited 1 time in total.
1 KUDOS received
Manager
Manager
User avatar
Joined: 08 Sep 2010
Posts: 237
Location: India
WE 1: 6 Year, Telecom(GSM)
Followers: 4

Kudos [?]: 80 [1] , given: 21

Re: M02 Q31 (DS) [#permalink] New post 29 Sep 2010, 09:50
1
This post received
KUDOS
supoose the two digit number is xy

so the value of the number will be 10x + y which is divisible by 3 ( x=1 to 9 and y = 1to 9)

Now with the 1st option x+y=18 and the only case is 99 which is more than 50.

For the option 2, for example we can take 63 and 36 both are satisfying so we cant deduce the number.


Hence the Answer should be A.
_________________

Consider KUDOS if You find it good

CEO
CEO
User avatar
Joined: 29 Aug 2007
Posts: 2501
Followers: 53

Kudos [?]: 508 [0], given: 19

Re: M02 Q31 (DS) [#permalink] New post 16 Feb 2009, 21:40
river wrote:
GMAT TIGER,
I agree with you. First of all, the number -99 is a negative integer with 2 digits (9 and 9). A digit is an integer from 0 to 9. There is no "negative digit", so we can't have a digit equal to -9.

So, from what I understand, the GMATclub answer to that question is wrong, right? It should be E instead of A.

(Indeed, even for the case of -9 and 9, the sum is 0, which i a multiple of 18, as 18*0=0.. but that's not part of this solution).


That should be unless there is nothing hidden issues related digit/integer. I am little skeptical about -99.:!:
_________________

Verbal: new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html


GT

Intern
Intern
avatar
Joined: 15 Dec 2008
Posts: 37
Followers: 1

Kudos [?]: 15 [0], given: 0

Re: M02 Q31 (DS) [#permalink] New post 19 Feb 2009, 08:31
I am not very sure if for -99 we can take the digits as (-9,9) or (9,-9) because the -ve sign is for the whole number and not for individual digits I feel... Can somebody throw some light on this please... :?
Manager
Manager
avatar
Joined: 11 Apr 2009
Posts: 169
Followers: 2

Kudos [?]: 23 [0], given: 5

Re: M02 Q31 (DS) [#permalink] New post 27 May 2009, 14:37
I came across this problem. Can anyone throw some light on the choices? Is it A or E.
Things to consider: Is 0 a multiple of any integer? If true then 0 will be LCM of nay number.

Pl. help.........
Expert Post
Founder
Founder
User avatar
Affiliations: UA-1K, SPG-G, HH-D
Joined: 04 Dec 2002
Posts: 12284
Location: United States (WA)
GMAT 1: 750 Q49 V42
GPA: 3.5
WE: Information Technology (Hospitality and Tourism)
Followers: 2297

Kudos [?]: 9055 [0], given: 3678

GMAT ToolKit User Premium Member CAT Tests
Re: M02 Q31 (DS) [#permalink] New post 27 May 2009, 15:43
Expert's post
gmatprep09 wrote:
I came across this problem. Can anyone throw some light on the choices? Is it A or E.
Things to consider: Is 0 a multiple of any integer? If true then 0 will be LCM of nay number.

Pl. help.........



Have you considered purchasing GMAT Club Tests Access? You would get access to the official answers and explanations.
_________________

Founder of GMAT Club

Just starting out with GMAT? Start here... | Want to know your GMAT Score? Try GMAT Score Estimator
Need GMAT Book Recommendations? Best GMAT Books

Co-author of the GMAT Club tests

Have a blog? Feature it on GMAT Club!

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Intern
Intern
avatar
Joined: 10 Oct 2006
Posts: 3
Followers: 0

Kudos [?]: 0 [0], given: 0

Re: M02 Q31 (DS) [#permalink] New post 23 Aug 2009, 15:40
bb wrote:
gmatprep09 wrote:
I came across this problem. Can anyone throw some light on the choices? Is it A or E.
Things to consider: Is 0 a multiple of any integer? If true then 0 will be LCM of nay number.

Pl. help.........



Have you considered purchasing GMAT Club Tests Access? You would get access to the official answers and explanations.



so what's the verdict bb?

the explanation concludes that 99 IS indeed THE only two digit number that justifies the sufficiency of S1. It doesn't, however, address the possibility of having 0 as a multiple of 18.
Intern
Intern
avatar
Joined: 30 Aug 2010
Posts: 11
Location: INDIA
Followers: 0

Kudos [?]: 0 [0], given: 0

Re: M02 Q31 (DS) [#permalink] New post 27 Sep 2010, 09:53
IMO A.

Agree with rohansherry...
Intern
Intern
avatar
Joined: 02 Apr 2010
Posts: 48
Location: Mumbai
Followers: 1

Kudos [?]: 6 [0], given: 0

Re: M02 Q31 (DS) [#permalink] New post 28 Sep 2010, 18:35
I opted A but, since x = y = 9 from first statement, the two digit number can be -99 or 99 that is divisible by 3. One is less than 50 and other is greater than 50.

Can someone clear this contention?
_________________

Consider kudos for good explanations.

Manager
Manager
User avatar
Joined: 25 Jun 2008
Posts: 129
Concentration: General Management, Technology
Followers: 3

Kudos [?]: 25 [0], given: 5

Re: M02 Q31 (DS) [#permalink] New post 29 Sep 2010, 22:08
This is a Yes/No Data Sufficiency question, if you can answer yes or no to the options then the statement would be sufficient. If you can't answer definitively, then the statement is not sufficient.

If x and y represent digits of a two digit number divisible by 3, is the two digit number less than 50?

1. Sum of the digits is a multiple of 18
2. Product of the digits is a multiple of 9


1) Only option that answers this is 99. Answer to statement 1 is no, therefore it is sufficient.

2) 36 and 63 both meet the criteria for statement 2, therefore it is not sufficient.

Answer is A
Intern
Intern
avatar
Joined: 01 May 2011
Posts: 10
Followers: 0

Kudos [?]: 1 [0], given: 1

Re: M02 Q31 (DS) [#permalink] New post 06 Sep 2011, 23:11
mbasaikiran wrote:
I opted A but, since x = y = 9 from first statement, the two digit number can be -99 or 99 that is divisible by 3. One is less than 50 and other is greater than 50.

Can someone clear this contention?

E for same reason
digits 9;9 - everyone agree
what nubmers can be made of these two?
clearly +(99) and -(99)
so E

about "every number multiple of 0"
so sum of the digits should be 0
the number that has the sum 0 is "00"
but there is no such a number
Re: M02 Q31 (DS)   [#permalink] 06 Sep 2011, 23:11
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic Q31? saifa08 4 05 Jul 2013, 05:32
38 Experts publish their posts in the topic m02#24 bigfernhead 14 05 Nov 2008, 07:21
20 Experts publish their posts in the topic m02#8 bigfernhead 16 03 Nov 2008, 15:24
1 Experts publish their posts in the topic M02 Q11 DS idleking 20 27 Aug 2008, 17:06
1 Factoring...? (m02 #8) Liquid 5 27 Feb 2008, 21:50
Display posts from previous: Sort by

M02 Q31 (DS)

  Question banks Downloads My Bookmarks Reviews Important topics  

Go to page    1   2    Next  [ 27 posts ] 

Moderators: Bunuel, WoundedTiger



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

Powered by phpBB © phpBB Group and phpBB SEO

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®.