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

It is currently 31 Jul 2015, 05:27
GMAT Club Tests

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

What is the 25th digit to the right of the decimal point in

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28781
Followers: 4592

Kudos [?]: 47380 [0], given: 7123

What is the 25th digit to the right of the decimal point in [#permalink] New post 13 Aug 2012, 06:06
Expert's post
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

87% (01:38) correct 13% (00:38) wrong based on 552 sessions
Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28781
Followers: 4592

Kudos [?]: 47380 [1] , given: 7123

Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 13 Aug 2012, 06:06
1
This post received
KUDOS
Expert's post
SOLUTION

What is the 25th digit to the right of the decimal point in the decimal form of 6/11?

(A) 3
(B) 4
(C) 5
(D) 6
(E) 7

\(\frac{6}{11}=0.5454...\).

Every odd-numbered digit, to the right of the decimal point, is 5, thus 25th (odd) digit will also be 5.

Answer: C.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis ; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) ; 12. 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?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

Current Student
avatar
Joined: 18 Jun 2012
Posts: 145
Concentration: Healthcare, General Management
GMAT Date: 09-14-2012
Followers: 1

Kudos [?]: 15 [0], given: 1

Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 13 Aug 2012, 06:52
6/11=0.54545454 repeating, with 5 occuring at 1,3,5,7 etc. So the 25th digit will be 5.
1 KUDOS received
Senior Manager
Senior Manager
avatar
Joined: 14 May 2011
Posts: 277
Location: Costa Rica
Concentration: Healthcare, International Business
GMAT 1: 640 Q V0
GMAT 2: 710 Q42 V45
GMAT 3: 740 Q48 V42
GMAT 4: Q V0
GMAT 5: Q V0
GPA: 3.3
WE: Research (Consulting)
Followers: 10

Kudos [?]: 82 [1] , given: 134

Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 16 Aug 2012, 10:48
1
This post received
KUDOS
C) 5
Same solution as above, but in case the repeating digits are more numerous then see:
1) Number of repeating digits (in this case 2 -> .5454..)
2) Divide the # of the digit you're supposed to view (25th digit) by # of repeats = (25/2)th digit
3) If no remainder, then its 4, if there's a Remainder = 1 then it has to be the next digit or 5, as in this case
_________________


How to improve your RC score, pls Kudo if helpful! http://gmatclub.com/forum/how-to-improve-my-rc-accuracy-117195.html
Work experience (as of June 2012)
2.5 yrs (Currently employed) - Mckinsey & Co. (US Healthcare Analyst)
2 yrs - Advertising industry (client servicing)

2 KUDOS received
Director
Director
avatar
Joined: 24 Aug 2009
Posts: 507
Schools: Harvard, Columbia, Stern, Booth, LSB,
Followers: 10

Kudos [?]: 477 [2] , given: 241

Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 16 Aug 2012, 11:35
2
This post received
KUDOS
6/11 results in a Non-terminating decimal equal to .545454......54
Every even place (2nd,4th,6th,,,,,,,,,24th) digit is 4.
Every Odd place (1,3,5.....25) digit is 5.
Thus thus the odd place digit is 5
Hence Answer C.
_________________

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

Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28781
Followers: 4592

Kudos [?]: 47380 [1] , given: 7123

Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 17 Aug 2012, 00:12
1
This post received
KUDOS
Expert's post
SOLUTION

What is the 25th digit to the right of the decimal point in the decimal form of 6/11?

(A) 3
(B) 4
(C) 5
(D) 6
(E) 7

\(\frac{6}{11}=0.5454...\).

Every odd-numbered digit, to the right of the decimal point, is 5, thus 25th (odd) digit will also be 5.

Answer: C.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis ; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) ; 12. 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?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

4 KUDOS received
Intern
Intern
avatar
Joined: 02 Aug 2013
Posts: 17
Followers: 1

Kudos [?]: 5 [4] , given: 1

Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 02 Aug 2013, 12:07
4
This post received
KUDOS
an easy way to find 6/11 in decimal terms

expand it by 9

(6*9)/(11*9) = 54/99

note that 54/99 is the fractional representation of circulating (recurring) decimal 0,545454...


___

I dunno how anyone else would of got 0.5454 etc without using a calculator
1 KUDOS received
Intern
Intern
avatar
Joined: 25 Oct 2013
Posts: 2
Followers: 0

Kudos [?]: 1 [1] , given: 2

GMAT ToolKit User
Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 03 Nov 2013, 12:13
1
This post received
KUDOS
But is there anyway to remember how to calculate 6/11 or 7/11 for that matter?I can't possibly remember all fractions...
Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28781
Followers: 4592

Kudos [?]: 47380 [1] , given: 7123

Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 03 Nov 2013, 12:18
1
This post received
KUDOS
Expert's post
Markster wrote:
But is there anyway to remember how to calculate 6/11 or 7/11 for that matter?I can't possibly remember all fractions...


Try to simply divide 6 by 11 to get 0.5454...

Else notice that 6/11=54/99=0.5454... Check Converting Decimals to Fractions here: math-number-theory-88376.html
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis ; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) ; 12. 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?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

Manager
Manager
avatar
Joined: 07 Apr 2014
Posts: 147
Followers: 1

Kudos [?]: 11 [0], given: 81

Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 09 Sep 2014, 22:57
Bunuel wrote:
What is the 25th digit to the right of the decimal point in the decimal form of 6/11?

(A) 3
(B) 4
(C) 5
(D) 6
(E) 7

Practice Questions
Question: 20
Page: 154
Difficulty: 600



multiply 9 on both 6 & 11 then u will get 54/99...

whatever 2 digit number divided 99 will have the same digits repeat... say here 0.5454....

25th digit will be 5....
Intern
Intern
avatar
Joined: 08 Apr 2014
Posts: 4
Followers: 0

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

GMAT ToolKit User
Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 29 Apr 2015, 05:29
Just want to be clear here. Are we expected to know non terminating fractions or expected to do the math of 6/11? I could do, but I felt it would be math intensive and wanted to avoid that. The rule that seemed relevant from the number theory link is that terminating fractions have a denominator that fits the 2^m*5^n formula. What's the best way to approach this, and what math is unnecessary? Please advise.
Intern
Intern
User avatar
Joined: 15 Mar 2015
Posts: 46
Followers: 1

Kudos [?]: 15 [0], given: 6

Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 29 Apr 2015, 08:37
I divided 6/11 and got to .545, after that I realized the pattern would repeat itself. As there's just two different digits the even decimals will be 5 and the odds will be 4. Thus 5 is the answer and C as the answer choice.
Expert Post
EMPOWERgmat Instructor
User avatar
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 3047
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Followers: 134

Kudos [?]: 848 [0], given: 54

Re: What is the 25th digit to the right of the decimal point in [#permalink] New post 04 May 2015, 18:39
Expert's post
Hi braveally,

The GMAT cannot realistically expect you to work through 25 digits one at a time, so this question MUST have a pattern to it.

There are certain pieces of information that you're expected to have memorized (formulas, math and grammar rules, etc.) and other types of information that would be beneficial to have memorized (fraction-to-decimal conversions, commonly tested 'patterns', etc.). It shouldn't be difficult to memorize the decimal equivalent of a set of fractions, BUT if you don't want to, then that's fine - the work will just take a little longer.

So the question in this case becomes "how quickly can you mathematically determine that 6/11 = .5454 repeating?" You were concerned that the work would be time-sensitive, so you didn't attempt it. But I'm curious about how quickly you COULD have done it. Grab a timer and find out. I bet it takes 10-15 seconds (at most) until you have the proof that you need.

GMAT assassins aren't born, they're made,
Rich
_________________

Official Guide 2016 Question Breakdown:
http://gmatclub.com/forum/empowergmat-blog-198415.html#p1527977

Rich Cohen
Rich.C@empowergmat.com
http://www.empowergmat.com

GMAT Club Verified Reviews for EMPOWERgmat & Special Discount

EMPOWERgmat Podcast - A Wild Secret About The GMAT Algorithm


Re: What is the 25th digit to the right of the decimal point in   [#permalink] 04 May 2015, 18:39
    Similar topics Author Replies Last post
Similar
Topics:
3 How many digits will be there to the right of the decimal vinnik 3 13 Apr 2013, 00:44
2 Experts publish their posts in the topic What is the 18th digit to the right of the decimal point Pansi 4 08 Nov 2012, 14:57
2 Experts publish their posts in the topic What is the 99th digit after the decimal point in the carcass 4 10 Mar 2012, 07:23
21 Experts publish their posts in the topic What is the tenth digit to the right of the decimal point gmatpapa 12 18 Feb 2011, 02:37
2 Experts publish their posts in the topic If the digits 37 in the decimal 0.00037 repeat indefinitely, aimingformba 9 15 Jul 2010, 21:37
Display posts from previous: Sort by

What is the 25th digit to the right of the decimal point in

  Question banks Downloads My Bookmarks Reviews Important topics  


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®.