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

It is currently 10 Feb 2016, 16:46
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

If S is the sum of reciprocals of a list of consecutive

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 04 Mar 2012
Posts: 46
Followers: 0

Kudos [?]: 123 [0], given: 10

If S is the sum of reciprocals of a list of consecutive [#permalink] New post 16 May 2012, 08:35
4
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

68% (01:45) correct 32% (00:52) wrong based on 169 sessions
If S is the sum of reciprocals of a list of consecutive integers from 45 to 54, inclusive, S is approximately equal to

A. 0.1
B. 0.2
C. 0.3
D. 0.4
E. 0.5
[Reveal] Spoiler: OA

Last edited by Bunuel on 13 Aug 2014, 02:12, edited 1 time in total.
Added the OA.
Expert Post
2 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 31299
Followers: 5356

Kudos [?]: 62347 [2] , given: 9454

Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 16 May 2012, 08:42
2
This post received
KUDOS
Expert's post
4
This post was
BOOKMARKED
gmihir wrote:
If S is the sum of reciprocals of a list of consecutive integers from 45 to 54, inclusive, S is approximately equal to

A. 0.1
B. 0.2
C. 0.3
D. 0.4
E. 0.5

Sorry, don't have an official answer.


We need to find the approximate value of 1/45+1/46+1/47+1/48+1/49+1/50+1/51+1/52+1/53+1/54. Now, the sum of these 10 terms will be very close to 10 times 1/50, which is 0.02*10=0.2.

Answer: B.
_________________

New to the Math Forum?
Please read this: 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: 24 Feb 2011
Posts: 7
Followers: 0

Kudos [?]: 0 [0], given: 37

Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 24 Aug 2012, 03:27
Are these kind of progressions tested on the GMAT?
1 KUDOS received
Retired Moderator
User avatar
Status: 2000 posts! I don't know whether I should feel great or sad about it! LOL
Joined: 04 Oct 2009
Posts: 1713
Location: Peru
Schools: Harvard, Stanford, Wharton, MIT & HKS (Government)
WE 1: Economic research
WE 2: Banking
WE 3: Government: Foreign Trade and SMEs
Followers: 82

Kudos [?]: 626 [1] , given: 109

Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 24 Aug 2012, 09:09
1
This post received
KUDOS
+1 B

All those numbers are close to 0.02.

Amogh: yes, that would be a GMAT question. You don't have to calculate, just estimate.
_________________

"Life’s battle doesn’t always go to stronger or faster men; but sooner or later the man who wins is the one who thinks he can."

My Integrated Reasoning Logbook / Diary: my-ir-logbook-diary-133264.html

GMAT Club Premium Membership - big benefits and savings

Intern
Intern
avatar
Joined: 11 Jul 2012
Posts: 46
Followers: 0

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

Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 05 Nov 2012, 14:18
I got 0.2 too (B). Please help. Here is my approach
(1/45) + (1/46) + .....+(1/54) = (45-44)/45 +(46-45)/46 +.....+(54-53)/54
= 10 -(44/45 + 45/46 + ...53/54). Each term in the bracket is > 0.977, and there are ten of them. Then their sum is roughly 9.8
10-9.8 = 0.2. But is this doable in 2 mn under stress and heat?
Brother Karamazov



Brother Karamazov
Intern
Intern
avatar
Status: wants to beat the gmat
Joined: 18 Jul 2012
Posts: 20
Location: United States
Followers: 0

Kudos [?]: 7 [0], given: 1

Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 06 Nov 2012, 12:47
my method was 1/45 + 1/46 + ... => 10/45 ~ 2/9 ~ .2
2 KUDOS received
Senior Manager
Senior Manager
User avatar
Joined: 13 Aug 2012
Posts: 464
Concentration: Marketing, Finance
GMAT 1: Q V0
GPA: 3.23
Followers: 20

Kudos [?]: 321 [2] , given: 11

GMAT ToolKit User
Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 19 Dec 2012, 02:59
2
This post received
KUDOS
2
This post was
BOOKMARKED
gmihir wrote:
If S is the sum of reciprocals of a list of consecutive integers from 45 to 54, inclusive, S is approximately equal to

A. 0.1
B. 0.2
C. 0.3
D. 0.4
E. 0.5

Sorry, don't have an official answer.


Solved this using Bunuel's technique that I saw on another similar problem.

S = \(\frac{1}{45}+\frac{1}{46}+...+\frac{1}{54}\)

Get number of terms: \(54 - 45 + 1 = 10\)

Get lower limit: \(10*\frac{1}{54}=\frac{5}{27}=0.18\)
Get upper limit: \(10*\frac{1}{45}=\frac{2}{9}=0.22\)

\(0.18<S<0.22\)

Answer: B
_________________

Impossible is nothing to God.

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 8208
Followers: 417

Kudos [?]: 111 [0], given: 0

Top 10 in overall
Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 12 Aug 2014, 14:28
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

1 KUDOS received
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1854
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Followers: 31

Kudos [?]: 1359 [1] , given: 193

Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 12 Aug 2014, 20:39
1
This post received
KUDOS
gmihir wrote:
If S is the sum of reciprocals of a list of consecutive integers from 45 to 54, inclusive, S is approximately equal to

A. 0.1
B. 0.2
C. 0.3
D. 0.4
E. 0.5

Sorry, don't have an official answer.


Bunuel, Kindly update OA for this question (Answer = B)
Thanks
_________________

Kindly press "+1 Kudos" to appreciate :)

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 31299
Followers: 5356

Kudos [?]: 62347 [0], given: 9454

Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 13 Aug 2014, 02:14
Expert's post
PareshGmat wrote:
gmihir wrote:
If S is the sum of reciprocals of a list of consecutive integers from 45 to 54, inclusive, S is approximately equal to

A. 0.1
B. 0.2
C. 0.3
D. 0.4
E. 0.5

Sorry, don't have an official answer.


Bunuel, Kindly update OA for this question (Answer = B)
Thanks

_____________
Done. Thank you.
_________________

New to the Math Forum?
Please read this: 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

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 8208
Followers: 417

Kudos [?]: 111 [0], given: 0

Top 10 in overall
Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 08 Nov 2015, 19:48
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

Expert Post
Manager
Manager
User avatar
Joined: 20 Aug 2015
Posts: 237
Location: India
GMAT 1: 760 Q50 V42
Followers: 6

Kudos [?]: 73 [0], given: 7

Re: If S is the sum of reciprocals of a list of consecutive [#permalink] New post 09 Nov 2015, 02:15
Expert's post
gmihir wrote:
If S is the sum of reciprocals of a list of consecutive integers from 45 to 54, inclusive, S is approximately equal to

A. 0.1
B. 0.2
C. 0.3
D. 0.4
E. 0.5


Such questions do not test your calculations. (In fact most of GMAT questions) They test your logic and how easily can you simplify a problem.
That is why an approximate result is asked and not the absolute value.


Out of the given numbers, from 45 to 54, carrying out calculations with 50 would be easiest.

Hene instead of 1/45 + 1/46 + ... 1/50 + ... + 1/54,
We can increase some terms and decrease some terms by changing the numbers with 50

Hence we have a sequence = 1/50 + 1/50 + ... + 1/50 (Total 20 terms)
= 10/50 = 1/5 = 0.2 approximately
Option B
_________________

Reach out to us at bondwithus@gmatify.com

Image

Re: If S is the sum of reciprocals of a list of consecutive   [#permalink] 09 Nov 2015, 02:15
    Similar topics Author Replies Last post
Similar
Topics:
44 Experts publish their posts in the topic If K is the sum of reciprocals of the consecutive integers fozzzy 20 07 Jan 2013, 02:05
129 Experts publish their posts in the topic M is the sum of the reciprocals of the consecutive integers Walkabout 23 06 Dec 2012, 08:42
10 M is the sum of the reciprocals of the consecutive integers sarb 2 07 Jun 2012, 00:14
4 Experts publish their posts in the topic If the sum of the first four numbers in a list of six consecutive even gmatbull 9 04 Aug 2010, 10:03
21 Experts publish their posts in the topic Which of the following could be the sum of the reciprocals milind1979 14 31 Mar 2009, 20:29
Display posts from previous: Sort by

If S is the sum of reciprocals of a list of consecutive

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| 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®.