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

It is currently 18 Jun 2018, 21:36

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If the unit digit of the positive integer n is

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

Hide Tags

Manager
Manager
avatar
Joined: 18 Feb 2015
Posts: 86
If the unit digit of the positive integer n is [#permalink]

Show Tags

New post 10 Aug 2016, 11:30
4
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

75% (00:44) correct 25% (01:22) wrong based on 194 sessions

HideShow timer Statistics

If the unit digit of the positive integer n is 5, what is the tens digit of n?

(1) The tens digit of n+5 is 7.
(2) The tens digit of n-6 is 5.
Intern
Intern
avatar
B
Joined: 06 May 2015
Posts: 24
Re: If the unit digit of the positive integer n is [#permalink]

Show Tags

New post 10 Aug 2016, 12:13
1
it is given that unit digit is 5 so No. can be 5, 15, 65,75or 85 .i.e anything that unit digit is 5
1st stmt- N+5=tenth digit is 7
so only two digit integer if n=65 +5=70 ( tenth digit is 7) while 75+5=80
so it confirm that 65 is that No.
2nd Stmt If 6 is reduced from N that tenth digit will be 5 here also 65-6=59( tenth digit is 5)

so its D
Retired Moderator
avatar
G
Joined: 26 Nov 2012
Posts: 599
Premium Member
If the unit digit of the positive integer n is [#permalink]

Show Tags

New post 10 Aug 2016, 12:24
shravan2025 wrote:
it is given that unit digit is 5 so No. can be 5, 15, 65,75or 85 .i.e anything that unit digit is 5
1st stmt- N+5=tenth digit is 7
so only two digit integer if n=65 +5=70 ( tenth digit is 7) while 75+5=80
so it confirm that 65 is that No.
2nd Stmt If 6 is reduced from N that tenth digit will be 5 here also 65-6=59( tenth digit is 5)

so its D


Good one...Tried in the same way..

Here the number is 65 and its tens digits is 6 and units 5..... In GMAT if stat 1 and stat 2 individually sufficient means ..we get same result from both.
Expert Post
Math Revolution GMAT Instructor
User avatar
D
Joined: 16 Aug 2015
Posts: 5575
GMAT 1: 800 Q59 V59
GPA: 3.82
Re: If the unit digit of the positive integer n is [#permalink]

Show Tags

New post 10 Aug 2016, 20:47
There is 1 variable (the tens digit of n) in the original condition. In order to match the number of variables and the number of equations, we need 1 equation. Since con 1) and con 2) each has 1 equation, there is a high chance that D is the correct answer.
In case of con 1), the tens digit is always 6. The answer is unique and the condition is sufficient.
In case of con 2), the tens digit is always 6 as well. The answer is unique and the condition is sufficient. Hence, the correct answer is D.
Attachments

variable approach's answer probability.jpg
variable approach's answer probability.jpg [ 219.74 KiB | Viewed 3157 times ]


_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Manager
Manager
avatar
S
Joined: 21 Apr 2016
Posts: 185
GMAT ToolKit User Reviews Badge
Re: If the unit digit of the positive integer n is [#permalink]

Show Tags

New post 10 Aug 2016, 21:03
HarveyKlaus wrote:
If the unit digit of the positive integer n is 5, what is the tens digit of n?

(1) The tens digit of n+5 is 7.
(2) The tens digit of n-6 is 5.


let the tens digit be t

From (1)

t5
+ 5
----
70 => only value for t is 6

From (2)

t5
- 6
----
59 => only value for t is 6

Therefore D
Top Contributor
Director
Director
User avatar
B
Status: I don't stop when I'm Tired,I stop when I'm done
Joined: 11 May 2014
Posts: 554
Location: Bangladesh
Concentration: Finance, Leadership
GPA: 2.81
WE: Business Development (Real Estate)
Re: If the unit digit of the positive integer n is [#permalink]

Show Tags

New post 11 Aug 2016, 01:02
Top Contributor
HarveyKlaus wrote:
If the unit digit of the positive integer n is 5, what is the tens digit of n?

(1) The tens digit of n+5 is 7.
(2) The tens digit of n-6 is 5.



(1)The tens digit of n+5 is 7;value of n ranged from 65 to 72,Since unit digit is 5,thus n=65,so tens digit of n=6,Sufficient

(2) The tens digit of n-6 is 5;value of n ranged from 56 to 65,Since unit digit is 5,thus n=65,so tens digit of n=6,Sufficient


Correct Answer D
_________________

Md. Abdur Rakib

Please Press +1 Kudos,If it helps
Sentence Correction-Collection of Ron Purewal's "elliptical construction/analogies" for SC Challenges

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 6995
Premium Member
Re: If the unit digit of the positive integer n is [#permalink]

Show Tags

New post 30 Sep 2017, 01:19
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: If the unit digit of the positive integer n is   [#permalink] 30 Sep 2017, 01:19
Display posts from previous: Sort by

If the unit digit of the positive integer n is

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


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®.