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

It is currently 15 Dec 2018, 16:00

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 in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • $450 Tuition Credit & Official CAT Packs FREE

     December 15, 2018

     December 15, 2018

     10:00 PM PST

     11:00 PM PST

    Get the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299)
  • FREE Quant Workshop by e-GMAT!

     December 16, 2018

     December 16, 2018

     07:00 AM PST

     09:00 AM PST

    Get personalized insights on how to achieve your Target Quant Score.

If the productivity of a brigade grows by 10% when the numbe

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

Hide Tags

Director
Director
avatar
Joined: 09 Aug 2006
Posts: 730
If the productivity of a brigade grows by 10% when the numbe  [#permalink]

Show Tags

New post 07 Jan 2008, 08:14
8
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

70% (01:18) correct 30% (01:34) wrong based on 303 sessions

HideShow timer Statistics

If the productivity of a brigade grows by 10% when the number of the workers in the brigade is increased by one, then which of the following is closest to the ratio of the productivity of a 12-person brigade to that of a 10-person brigade?

A. 0.21
B. 0.82
C. 1.20
D. 1.21
E. 1.44
Manager
Manager
avatar
Joined: 20 Jun 2007
Posts: 147
Re: PS: Ratio of Productivity  [#permalink]

Show Tags

New post 07 Jan 2008, 08:20
1
It's like compound interest.

Growth of 10% from 10 is indeed 1, to 11.
But growth of 10% from 11 is indeed 1.1, to 12.1.
Manager
Manager
User avatar
Joined: 01 Jan 2008
Posts: 216
Schools: Booth, Stern, Haas
Re: PS: Ratio of Productivity  [#permalink]

Show Tags

New post 07 Jan 2008, 08:28
GK_Gmat wrote:
The productivity of a brigade grows by 10% when the number of the workers in the brigade is increased by one. Which of the following is closest to the ratio of the productivity of a 12-men brigade to that of a 10-men brigade?
0.21
0.82
1.20
1.21
1.44

Can someone please explain why C is wrong? Thanks.


I agree with raffie, C is wrong because 1.2 is ratio if each 10% is added to the tenth worker rather than eleventh which is wrong, twelves man adds 10% to the total 11 workers
Director
Director
User avatar
Joined: 12 Jul 2007
Posts: 843
Re: PS: Ratio of Productivity  [#permalink]

Show Tags

New post 07 Jan 2008, 09:21
1
The most powerful force in the universe is compound interest - Albert Einstein :-D
SVP
SVP
avatar
Joined: 04 May 2006
Posts: 1665
Schools: CBS, Kellogg
Premium Member
Re: PS: Ratio of Productivity  [#permalink]

Show Tags

New post 07 Jan 2008, 18:19
1
1
GK_Gmat wrote:
The productivity of a brigade grows by 10% when the number of the workers in the brigade is increased by one. Which of the following is closest to the ratio of the productivity of a 12-men brigade to that of a 10-men brigade?
0.21
0.82
1.20
1.21
1.44

Can someone please explain why C is wrong? Thanks.


D,
productivity of a 10-men brigade assumed is 10
when added 1 man, it is increasing by 10*1.1 =11
when added 1 more, it s increasing by 11*1.1 =12.1= productivity of a 12-men brigade
so, the ratio=12.1/10 =1.21
_________________

GMAT Club Premium Membership - big benefits and savings

Manager
Manager
avatar
Joined: 16 Feb 2012
Posts: 174
Concentration: Finance, Economics
GMAT ToolKit User
Re: The productivity of a brigade grows by 10% when the number  [#permalink]

Show Tags

New post 15 May 2013, 21:53
This is the question from GMATClub test. The explanation from the solution of the question is excellent, but I want to know is there more than one way to solve this question.

On the GMATClub test the explanation is next:
B = 10-men brigade
p = increase in the productivity = 10%

Solution: B x p = B x 1.1 = 1.1B -------> the productivity of 11 men brigade
1.1B x p = 1.1B x 1.1 = 1.21B -----> the productivity of 12 men brigade

The ratio of the productivity of a 12-men brigade to that of a 10-men brigade = 1.21B/B = 1.21
_________________

Kudos if you like the post!

Failing to plan is planning to fail.

Veritas Prep GMAT Instructor
User avatar
P
Joined: 16 Oct 2010
Posts: 8678
Location: Pune, India
Re: The productivity of a brigade grows by 10% when the number  [#permalink]

Show Tags

New post 16 May 2013, 07:42
4
Stiv wrote:
This is the question from GMATClub test. The explanation from the solution of the question is excellent, but I want to know is there more than one way to solve this question.

On the GMATClub test the explanation is next:
B = 10-men brigade
p = increase in the productivity = 10%

Solution: B x p = B x 1.1 = 1.1B -------> the productivity of 11 men brigade
1.1B x p = 1.1B x 1.1 = 1.21B -----> the productivity of 12 men brigade

The ratio of the productivity of a 12-men brigade to that of a 10-men brigade = 1.21B/B = 1.21


In percentages, you can assume a value of 100. It simplifies the thought process.

If you increase the brigade by 1 worker, productivity grows by 10%. So say initial productivity is 100. If one more worker joins, productivity will be 110. If one more joins it will be 121 etc.
Ratio of productivity of 12 person to 10 person must be 121/100 = 1.21 (whenever there is a difference of 2 in the number of people, the ratio of productivity will be 1.21 assuming positive number of people)


Also, this is a successive percentage increase so you can use the formula: a + b + ab/100 = 10 + 10 + 10*10/100 = 21% increase.
Hence the required ratio is 121/100 = 1.21
_________________

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 >

Manager
Manager
avatar
Joined: 16 Feb 2012
Posts: 174
Concentration: Finance, Economics
GMAT ToolKit User
Re: If the productivity of a brigade grows by 10% when the numbe  [#permalink]

Show Tags

New post 16 May 2013, 23:51
Thank you, that is very helpful! :) It's important to remember new ideas about solving a problem...
_________________

Kudos if you like the post!

Failing to plan is planning to fail.

VP
VP
User avatar
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1063
Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
GMAT ToolKit User
Re: Best or Worste Word Problem  [#permalink]

Show Tags

New post 20 May 2013, 13:27
\(\frac{P_{12}}{P{10}}=?\)

\(P_{12}=P{10}+2\) each person inrease the prod by 10% so 2 people increase the prod by (1+10%)*(1+10%)=1.21

\(\frac{1.21P_{10}}{P{10}}=1.21\)

D

hope it's clear let me know
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

Manager
Manager
User avatar
Status: *Lost and found*
Joined: 25 Feb 2013
Posts: 121
Location: India
Concentration: General Management, Technology
GMAT 1: 640 Q42 V37
GPA: 3.5
WE: Web Development (Computer Software)
GMAT ToolKit User
Re: Best or Worste Word Problem  [#permalink]

Show Tags

New post 20 May 2013, 13:27
madzstar wrote:
If the productivity of a brigade grows by 10% when the number of the workers in the brigade is increased by one, then which of the following is closest to the ratio of the productivity of a 12-person brigade to that of a 10-person brigade?

A.0.21
B.0.82
C.1.20
D.1.21
E.1.44

Could you please help explain the answer to this


As the OA mentions, the answer is [D].

Let the total number of workers be x in the brigade and the corresponding productivity be p.
Now as per the question, if the worker number increases to x + 1 the final productivity is 110*p/100 ****10% rise in productivity.
Now further applied, if the number further increases by 1 i.e. x+2, the final productivity would be 110*110*p/100*100 => 121*p/100

Hence, when the ratio is taken between the productivity of x+2 and x workers, the value is 121/100 i.e 1.21. ****since its generalized, if x = 8, x+2 =10.

Hope the above explains your queries over the question! :)

Regards,
Arpan
_________________

Feed me some KUDOS! :) :) *always hungry*

My Thread : Recommendation Letters

Manager
Manager
User avatar
Joined: 18 May 2012
Posts: 81
Concentration: Finance, Marketing
Re: If the productivity of a brigade grows by 10% when the numbe  [#permalink]

Show Tags

New post 20 May 2013, 14:11
New Productivity after 1 worker is increased = 1+10/100 = 1.1
Cascaded Increase = 1.1 * 1.1 ....
=> Productivity Increase for 12 (1.1)^12
--------------------------------- = ------------ = (1.1)^2 = 1.21
Productivity Increase for 10 (1.1)^10


Hence IMO (D)
_________________

Focusing on apps..
|GMAT Debrief|TOEFL Debrief|

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9165
Premium Member
Re: If the productivity of a brigade grows by 10% when the numbe  [#permalink]

Show Tags

New post 17 Sep 2018, 06:35
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

GMAT Club Bot
Re: If the productivity of a brigade grows by 10% when the numbe &nbs [#permalink] 17 Sep 2018, 06:35
Display posts from previous: Sort by

If the productivity of a brigade grows by 10% when the numbe

  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®.