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

It is currently 18 Sep 2018, 20:23

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.

Close

Request Expert Reply

Confirm Cancel

If N = 1234 and represents the units digit, is N a multiple of 5?

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

Hide Tags

Manager
Manager
avatar
Joined: 13 Aug 2010
Posts: 183
If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 11 Oct 2010, 19:06
9
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

31% (00:42) correct 69% (00:42) wrong based on 334 sessions

HideShow timer Statistics

If \(N = 1234@\) and @ represents the units digit, is N a multiple of 5?

(1) @! is not divisible by 5
(2) @ is divisible by 9

My understanding is that if @! is not divisible by 5 then @ is less than 5 so not divisible by 5

and since @ is divisible by 9, it is not divisible by 5, since 9 is a prime number, so i picked D. but the OA is something else .can some one please explain. Thank you
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49208
If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 11 Oct 2010, 19:41
5
3
prab wrote:
If N=1233AND @ represents the units digit, is @ a multiple of 5?

1. @! is not divisible by 5
2 @ is divisible by 9

My understanding is that if @! is not divisible by 5 then @ is less than 5 so not divisible by 5

and since @ is divisible by 9, it is not divisible by 5, since 9 is a prime number, so i picked D. but the OA is something else .can some one please explain. Thank you


Red parts are not correct.

If \(N = 1234@\) and @ represents the units digit, is N a multiple of 5?

For \(1233@\) to be divisible by 5 symbol @ should represent either 0 or 5. So the question asks whether @ equals to 0 or 5.

(1) @! is not divisible by 5 --> \(@\) can be 0, 1, 2, 3, or 4 (note that \(0!=1\)). Not sufficient.
(2) @ is divisible by 9 --> \(@\) can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient.

(1)+(2) Intersection of the values for @ from (1) and (2) is @=0. Sufficient.

Answer: C.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

General Discussion
SVP
SVP
User avatar
Status: Three Down.
Joined: 09 Jun 2010
Posts: 1868
Concentration: General Management, Nonprofit
GMAT ToolKit User
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 11 Oct 2010, 19:32
prab wrote:
If N=1233@ and @ represents the units digit, is [highlight]@ a multiple of 5[/highlight]?

1. @! is not divisible by 5
2 @ is divisible by 9

My understanding is that if @! is not divisible by 5 then @ is less than 5 so not divisible by 5

and since @ is divisible by 9, it is not divisible by 5, since 9 is a prime number, so i picked D. but the OA is something else .can some one please explain. Thank you


A multiple of 5 means it can be 0 or 5.

So when you're considering statement 1, it says that @! is not divisible by 5, ruling out the option that it's 5. It could still be zero.

However the second statement negates this, and hence helps reach a conclusion.

In my opinion, this is poorly worded. But, yeah.
Manager
Manager
avatar
Joined: 13 Aug 2010
Posts: 183
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 11 Oct 2010, 20:44
thank you, for your explanations. Well i didn't know there was any thing like 0!, but since there is, option C is correct.
Manager
Manager
avatar
Joined: 25 Aug 2010
Posts: 67
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 12 Oct 2010, 10:31
very good explanation.. i was expecting ! also a number... and i wanted to give ans as E.

But once i saw explanation from Bunuel, understood better...
Intern
Intern
User avatar
Joined: 10 Jul 2010
Posts: 36
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 12 Oct 2010, 21:27
Bunuel I missed "0" :oops:
Senior Manager
Senior Manager
avatar
Joined: 24 Mar 2011
Posts: 391
Location: Texas
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 17 May 2011, 12:10
1
If \(N = 1234@\) and \(@\) represents the units digit, is \(N\) a multiple of 5?

\(@!\) is not divisible by 5
\(@\) is divisible by 9
Veritas Prep GMAT Instructor
User avatar
P
Joined: 16 Oct 2010
Posts: 8278
Location: Pune, India
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 17 May 2011, 13:44
2
1
agdimple333 wrote:
If \(N = 1234@\) and \(@\) represents the units digit, is \(N\) a multiple of 5?

\(@!\) is not divisible by 5
\(@\) is divisible by 9


This is how you would analyze this question:

N = 1234@
Question: Is N a multiple of 5?
How do you figure whether a number is a multiple of 5 or not? You see the last digit to decide. If the last digit is 0/5, the number is divisible by 5, else it is not.

1. @! is not divisible by 5.
If @ = 0, 0! is 1 which is not divisible by 5. In this case N (12340) is divisible by 5.
If @ = 1, 1! is 1 which is not divisible by 5. In this case N (12341) is not divisible by 5.
So satisfying statement 1 is not sufficient to know whether N is divisible by 5.

2. @ is divisible by 9.
There are only 2 digits that are divisible by 9: 0 and 9
If @ = 0, N (12340) is divisible by 5.
If @ = 9, N (12349) is not divisible by 5.
So satisfying statement 2 is not sufficient to know whether N is divisible by 5.

Using both, The only value of @ that satisfies both statements is 0. (9! is divisible by 5 hence @=9 doesn't satisfy statement 1.)
If @ = 0, N (12340) is divisible by 5.
Hence, using both together, we know that N is divisible by 5. Sufficient.
Answer (C).
_________________

Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >

GMAT self-study has never been more personalized or more fun. Try ORION Free!

VP
VP
avatar
Status: There is always something new !!
Affiliations: PMI,QAI Global,eXampleCG
Joined: 08 May 2009
Posts: 1098
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 18 May 2011, 06:50
a the digit can be 0,1,2,3,4. 5! and above will be divisible by 5. Not sufficient.

b the number can be 0 | 9. Not sufficient.

a+b gives digit = 0. as 9! is divisible by 5.

Hence C.
_________________

Visit -- http://www.sustainable-sphere.com/
Promote Green Business,Sustainable Living and Green Earth !!

Intern
Intern
avatar
Joined: 09 May 2011
Posts: 17
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 18 May 2011, 10:57
Are you sure it's not N is divisible by 9 for the second piece of data?
Senior Manager
Senior Manager
avatar
Joined: 24 Mar 2011
Posts: 391
Location: Texas
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 18 May 2011, 11:08
jaschen27 wrote:
Are you sure it's not N is divisible by 9 for the second piece of data?


Yeh the Q is right, i have not hand typed it, but copied and pasted.
Intern
Intern
avatar
Joined: 28 Dec 2010
Posts: 19
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 08 Jan 2012, 06:03
Hi ,
I need to understand the 2nd statement . Is it right that '0' is divisible by 9 ? I thought this would be only 9 which is divisible by 9 . Please clarify .

Thanks,
VCG
Manager
Manager
User avatar
Joined: 29 Jul 2011
Posts: 94
Location: United States
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 08 Jan 2012, 18:52
Good one.

1. @! not divisible by 5 means @ = 0,1,2,3,4. 0 satisfies, but 1,2,3,4 does not suff.
2. @ div by 9 means @ = 0,9. Same as 1, insuff.

Together, @ = 0 is common, which is div by 5 as units digit of N. Suff.

C
_________________

I am the master of my fate. I am the captain of my soul.
Please consider giving +1 Kudos if deserved!

DS - If negative answer only, still sufficient. No need to find exact solution.
PS - Always look at the answers first
CR - Read the question stem first, hunt for conclusion
SC - Meaning first, Grammar second
RC - Mentally connect paragraphs as you proceed. Short = 2min, Long = 3-4 min

Intern
Intern
avatar
Joined: 28 Dec 2010
Posts: 19
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 09 Jan 2012, 03:56
I will still dont have the answer -
Is it right that '0' is divisible by 9 ? I thought this would be only 9 which is divisible by 9 .
Veritas Prep GMAT Instructor
User avatar
P
Joined: 16 Oct 2010
Posts: 8278
Location: Pune, India
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 09 Jan 2012, 04:33
verycoolguy33 wrote:
I will still dont have the answer -
Is it right that '0' is divisible by 9 ? I thought this would be only 9 which is divisible by 9 .


Yes, 0 is divisible by 9. 0/9 = 0
Similarly, 0 is divisible by 2, 234, 109845 etc
_________________

Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >

GMAT self-study has never been more personalized or more fun. Try ORION Free!

Current Student
avatar
Joined: 21 Aug 2010
Posts: 193
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 09 Jan 2012, 11:41
That was a really tricky one...what would be the level of that question by the way??
Veritas Prep GMAT Instructor
User avatar
P
Joined: 16 Oct 2010
Posts: 8278
Location: Pune, India
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 09 Jan 2012, 21:11
samramandy wrote:
That was a really tricky one...what would be the level of that question by the way??


In my opinion, it would be in 650 - 700 range.
_________________

Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >

GMAT self-study has never been more personalized or more fun. Try ORION Free!

Intern
Intern
avatar
Joined: 05 Oct 2013
Posts: 37
Location: United States
Concentration: General Management, Strategy
WE: Design (Transportation)
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 16 Sep 2014, 07:40
Bunuel wrote:
prab wrote:
If N=1233AND @ represents the units digit, is @ a multiple of 5?

1. @! is not divisible by 5
2 @ is divisible by 9

My understanding is that if @! is not divisible by 5 then @ is less than 5 so not divisible by 5

and since @ is divisible by 9, it is not divisible by 5, since 9 is a prime number, so i picked D. but the OA is something else .can some one please explain. Thank you


Red parts are not correct.

1233to be divisible by 5 symbol @ should represent either 0 or 5. So the question asks whether @ equals to 0 or 5.

(1) @! is not divisible by 5 --> @ can be 0, 1, 2, 3, or 4 (note that \(0!=1\)). Not sufficient.
(2) @ is divisible by 9 --> @ can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient.

(1)+(2) Intersection of the values for @ from (1) and (2) is @=0. Sufficient.

Answer: C.



Does it say that 1233Has to be divisible by 5 in the question???
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49208
If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 16 Sep 2014, 13:38
Arnav180 wrote:
Bunuel wrote:
prab wrote:
If N=1233AND @ represents the units digit, is @ a multiple of 5?

1. @! is not divisible by 5
2 @ is divisible by 9

My understanding is that if @! is not divisible by 5 then @ is less than 5 so not divisible by 5

and since @ is divisible by 9, it is not divisible by 5, since 9 is a prime number, so i picked D. but the OA is something else .can some one please explain. Thank you


Red parts are not correct.

1233to be divisible by 5 symbol @ should represent either 0 or 5. So the question asks whether @ equals to 0 or 5.

(1) @! is not divisible by 5 --> @ can be 0, 1, 2, 3, or 4 (note that \(0!=1\)). Not sufficient.
(2) @ is divisible by 9 --> @ can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient.

(1)+(2) Intersection of the values for @ from (1) and (2) is @=0. Sufficient.

Answer: C.



Does it say that 1233Has to be divisible by 5 in the question???


There was a typo in the original post. The question reads:

If \(N = 1234@\) and @ represents the units digit, is N a multiple of 5?
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
User avatar
Joined: 16 Jul 2015
Posts: 43
GMAT 1: 580 Q37 V33
GMAT 2: 580 Q39 V31
GMAT 3: 560 Q40 V28
GMAT 4: 580 Q37 V32
GMAT 5: 680 Q45 V37
GMAT 6: 690 Q47 V37
Re: If N = 1234 and represents the units digit, is N a multiple of 5?  [#permalink]

Show Tags

New post 27 Jun 2016, 07:38
0! is equal to 1? i know i might be asking a very basic question but please enlighten me
Re: If N = 1234 and represents the units digit, is N a multiple of 5? &nbs [#permalink] 27 Jun 2016, 07:38

Go to page    1   2    Next  [ 25 posts ] 

Display posts from previous: Sort by

If N = 1234 and represents the units digit, is N a multiple of 5?

  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®.