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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

If the productivity of a brigade grows by 10% when the numbe [#permalink]

Show Tags

07 Jan 2008, 09:14

7

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

25% (medium)

Question Stats:

68% (01:48) correct
32% (01:02) wrong based on 276 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?

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

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
_________________

Re: The productivity of a brigade grows by 10% when the number [#permalink]

Show Tags

15 May 2013, 22:53

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
_________________

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
_________________

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!

Re: If the productivity of a brigade grows by 10% when the numbe [#permalink]

Show Tags

27 Jun 2014, 07:14

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.
_________________

Re: If the productivity of a brigade grows by 10% when the numbe [#permalink]

Show Tags

13 Jan 2016, 01:30

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.
_________________

There’s something in Pacific North West that you cannot find anywhere else. The atmosphere and scenic nature are next to none, with mountains on one side and ocean on...

This month I got selected by Stanford GSB to be included in “Best & Brightest, Class of 2017” by Poets & Quants. Besides feeling honored for being part of...

Joe Navarro is an ex FBI agent who was a founding member of the FBI’s Behavioural Analysis Program. He was a body language expert who he used his ability to successfully...