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

It is currently 22 Oct 2018, 20:59

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 is a positive integer, what is the tens digit of n ?

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

Hide Tags

Manager
Manager
avatar
Joined: 02 Dec 2012
Posts: 177
If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 26 Dec 2012, 05:51
9
58
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

67% (01:17) correct 33% (01:36) wrong based on 2294 sessions

HideShow timer Statistics

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

(1) The hundreds digit of 10n is 6.
(2) The tens digit of n + 1 is 7.
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50042
Re: If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 26 Dec 2012, 05:53
5
13
If n is a positive integer, what is the tens digit of n ?

(1) The hundreds digit of 10n is 6. This implies that the tens digit of n is 6. Sufficient.

(2) The tens digit of n + 1 is 7. If n=70, then the tens digit of n is 7, but if n=69, then the tens digit of n is 6. Not sufficient.

Answer: A.
_________________

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

Most Helpful Community Reply
Senior Manager
Senior Manager
User avatar
Joined: 27 Jun 2012
Posts: 377
Concentration: Strategy, Finance
Schools: Haas EWMBA '17
Re: If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 14 Jan 2013, 00:45
11
2
fozzzy wrote:
How do you solve this one?


(1) The hundreds digit of 10n is 6
SUFFICIENT: If Hundred's place of 10n = 6 then Ten's place of n must be 6
e.g. n=68 tens place 6,
10n=680, hundreds place is 6

(2) The tens digit of n+1 is 7
INSUFFICIENT: If n=69; n+1=70 OR If n=77; n+1=77; i.e. n can have both 6 or 7 as tens place.

Hence choice(A) is the answer.
_________________

Thanks,
Prashant Ponde

Tough 700+ Level RCs: Passage1 | Passage2 | Passage3 | Passage4 | Passage5 | Passage6 | Passage7
Reading Comprehension notes: Click here
VOTE GMAT Practice Tests: Vote Here
PowerScore CR Bible - Official Guide 13 Questions Set Mapped: Click here
Finance your Student loan through SoFi and get $100 referral bonus : Click here

General Discussion
Manager
Manager
avatar
Joined: 18 May 2014
Posts: 59
Location: United States
Concentration: General Management, Other
GMAT Date: 07-31-2014
GPA: 3.99
WE: Analyst (Consulting)
Re: If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 18 May 2014, 11:11
6
2
let n = ABCD

tens digit = C

1. 10n = ABCD0
given, hundreds digit = 6 (or) C = 6 - sufficient

2. tens digit of n+1 = 7.

consider CD = 69 -> CD+1 = 70 -> C=6 (or)

consider CD = 71 ->CD+1 = 72 -> C = 7

2 cases possible - insuff.

Hence A
Manager
Manager
avatar
Joined: 07 Apr 2015
Posts: 168
If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 24 Jun 2015, 05:59
If n = 60, then the tens digit is 6
10*n = 600, then the tens digit is 0.

if n = 66, then the tens digit is 6
10*n = 660, then the tens digit is also 6.


Therefore 1. seems (incorrectly) not sufficient to me.

What am I doing wrong?


Damn it, it says "hundreds" digit in 1., not tens digit... :S
CEO
CEO
User avatar
D
Joined: 12 Sep 2015
Posts: 3031
Location: Canada
Re: If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 21 Jul 2016, 16:32
9
Top Contributor
6
Walkabout wrote:
If n is a positive integer, what is the tens digit of n ?

(1) The hundreds digit of 10n is 6.
(2) The tens digit of n + 1 is 7.


Target question: What is the tens digit of n?

Statement 1: The hundreds digit of 10n is 6
Notice what happens when we multiply any positive integer by 10:
34 x 10 = 340
60 x 10 = 600
128 x 10 = 1280
54629 x 10 = 546290
The tens digit in the original number becomes the hundreds digit in the new number.

So, if we're told that the hundreds digit of 10n is 6, then we know that the tens digit in n must be 6
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: The tens digit of n+1 is 7
There are several values of n that meet this condition. Here are two:
case a: n=69 in which case the tens digit of n is 6
case b: n=74 in which case the tens digit of n is 7
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT


Answer =

RELATED VIDEO

_________________

Brent Hanneson – GMATPrepNow.com
Image
Sign up for our free Question of the Day emails

Manager
Manager
User avatar
B
Joined: 23 Jun 2009
Posts: 184
Location: Brazil
GMAT 1: 470 Q30 V20
GMAT 2: 620 Q42 V33
GMAT ToolKit User Premium Member
If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 09 Sep 2016, 09:59
2
Here is my contribution with the reasoning a little more visual for those still struggling. :wink:
Attachments

Screenshot_20160909-140502.jpg
Screenshot_20160909-140502.jpg [ 504.88 KiB | Viewed 18507 times ]

Board of Directors
User avatar
V
Status: Stepping into my 10 years long dream
Joined: 18 Jul 2015
Posts: 3624
Premium Member Reviews Badge
Re: If N is a positive integer, what is the tens digit of N  [#permalink]

Show Tags

New post 13 Oct 2016, 00:10
Akuthiala wrote:
If N is a positive integer, what is the tens digit of N

(1) The hundreds digit of 10N is 6
(2) the tens digit of N+1 is 7


Answer will be A.

Statement 1 : Hundreds digit of 10N = Tens digit of N = 6. Hence, sufficient.

Statement 2: Tends digit of N+1 = 7.

Now in this case it may happen that Units digit was 9 and when 1 was added, we got Tends digit as 7. In that case answer will be 6. BUT if Units is less than 9, answer would be 7. Hence, Insufficient.
_________________

My GMAT Story: From V21 to V40
My MBA Journey: My 10 years long MBA Dream
My Secret Hacks: Best way to use GMATClub | Importance of an Error Log!
Verbal Resources: All SC Resources at one place | All CR Resources at one place
Blog: Subscribe to Question of the Day Blog

GMAT Club Inbuilt Error Log Functionality - View More.
New Visa Forum - Ask all your Visa Related Questions - here.

New! Best Reply Functionality on GMAT Club!



Find a bug in the new email templates and get rewarded with 2 weeks of GMATClub Tests for free

Check our new About Us Page here.

Retired Moderator
User avatar
B
Joined: 05 Jul 2006
Posts: 1727
GMAT ToolKit User Premium Member
Re: If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 13 Oct 2016, 01:10
Walkabout wrote:
If n is a positive integer, what is the tens digit of n ?

(1) The hundreds digit of 10n is 6.
(2) The tens digit of n + 1 is 7.


let the number be in the form

100a+10b+c = n what is 10b

from
1000a+100b+10c + d = 10n , now the 100s digit (b=6) in 10n is the tens in n .......suff

from 2

n+1 = 100a+ 10b+(c+1) ... if c+1>=10 then b = 6 but if c+1<10 b = 7... insuff

A
Intern
Intern
avatar
B
Joined: 25 May 2015
Posts: 18
If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 21 Mar 2018, 08:00
Walkabout wrote:
If n is a positive integer, what is the tens digit of n?

(1) The hundreds digit of 10n is 6.
(2) The tens digit of n + 1 is 7.


I am thinking that if we had the question as

If n is a positive number, what is the tenth digit of n?
(1) The hundredth digit of 10n is 6.
(2) The tenth digit of n + 1 is 7

A is no longer sufficient Am I Mistaken?


My answer would be B

What do you think guys!
DS Forum Moderator
avatar
P
Joined: 22 Aug 2013
Posts: 1348
Location: India
Premium Member
Re: If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 21 Mar 2018, 22:56
mohd_int wrote:
Walkabout wrote:
If n is a positive integer, what is the tens digit of n?

(1) The hundreds digit of 10n is 6.
(2) The tens digit of n + 1 is 7.


I am thinking that if we had the question as

If n is a positive number, what is the tenth digit of n?
(1) The hundredth digit of 10n is 6.
(2) The tenth digit of n + 1 is 7

A is no longer sufficient Am I Mistaken?


My answer would be B

What do you think guys!


Hello

Yes if you change the question to find the 'tenth' digit rather than 'tens' digit with the same set of statements as in this question, then the answer should be B, I think.

I suggest you post this question of yours to the DS forum.
Director
Director
User avatar
P
Joined: 09 Mar 2016
Posts: 951
If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 23 Aug 2018, 12:54
Bunuel wrote:
If n is a positive integer, what is the tens digit of n ?

(1) The hundreds digit of 10n is 6. This implies that the tens digit of n is 6. Sufficient.

(2) The tens digit of n + 1 is 7. If n=70, then the tens digit of n is 7, but if n=69, then the tens digit of n is 6. Not sufficient.

Answer: A.



How can ST ONE be sufficient IF The hundreds digit of 10n is 6

THE NUMBER CAN BE IN THIS CASE 10*60 = 600 the hundreds digits is 6 but tens digit is 0 ? :?
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50042
Re: If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 23 Aug 2018, 20:45
1
dave13 wrote:
Bunuel wrote:
If n is a positive integer, what is the tens digit of n ?

(1) The hundreds digit of 10n is 6. This implies that the tens digit of n is 6. Sufficient.

(2) The tens digit of n + 1 is 7. If n=70, then the tens digit of n is 7, but if n=69, then the tens digit of n is 6. Not sufficient.

Answer: A.



How can ST ONE be sufficient IF The hundreds digit of 10n is 6

THE NUMBER CAN BE IN THIS CASE 10*60 = 600 the hundreds digits is 6 but tens digit is 0 ? :?


If 10n = 10*60 = 600, then n = 60. The tens digit of n is 6.
_________________

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
avatar
Joined: 12 Jul 2018
Posts: 7
Og 18 ds 403  [#permalink]

Show Tags

New post 07 Sep 2018, 10:54
If n is a positive integer,what is the tens digit of n?
1. The hundreds digit of 10n is 6
2. The tens digit of n+1 is 7.
Can somebody please explain how the ans is A?

Sent from my Mi A1 using GMAT Club Forum mobile app
ISB, NUS, NTU Moderator
User avatar
G
Joined: 11 Aug 2016
Posts: 268
Reviews Badge CAT Tests
Re: If n is a positive integer, what is the tens digit of n ?  [#permalink]

Show Tags

New post 08 Sep 2018, 11:06
sakshi4391 wrote:
If n is a positive integer,what is the tens digit of n?
1. The hundreds digit of 10n is 6
2. The tens digit of n+1 is 7.
Can somebody please explain how the ans is A?

Sent from my Mi A1 using GMAT Club Forum mobile app


Hi sakshi
I'll try to help you out.

whenever we multiply any number with 10, the digits of the number shift their places by 1.

eg n=632. 10n=6320
In case of n,
Units Digit: 2
Tens Digit: 3
Hundred's Digit: 6

In case of 10n
In case of n,
Units Digit: 0
Tens Digit: 2
Hundred's Digit: 3

Now coming back to question We need to calculate the tens digit of n.
this will be the same as hundred's digit in 10n.
so using statement 1 we can calculate the answer. Hence Sufficient.

Statement 2 is insufficient because we do not know the units digit.
If the units digit is 9. then in n+1, 1 will be carried over to the tens place and hence increase the value by 1 unit. in this case the answer would be 6.
If the units digit is less than 9, then n+1 wil lhave the same tens digit as n. in this case our ans will be 7
Two different answers. Hence insufficient.

Answer: A
_________________

~R.
If my post was of any help to you, You can thank me in the form of Kudos!!

GMAT Club Bot
Re: If n is a positive integer, what is the tens digit of n ? &nbs [#permalink] 08 Sep 2018, 11:06
Display posts from previous: Sort by

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

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


Copyright

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®.