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:

Machine M, N, O working simultaneously Machine M can produce [#permalink]

Show Tags

26 Aug 2011, 07:30

3

This post received KUDOS

8

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

55% (hard)

Question Stats:

63% (03:08) correct
37% (02:15) wrong based on 163 sessions

HideShow timer Statistics

Machine M, N, O working simultaneously Machine M can produce x units in 3/4 of the time it takes machine N to produce the same amount of units. Machine N can produce x units in 2/3 the time it takes machine O to produce that amount of units. If all three machines are working simultaneously, what fraction of the total output is produced by machine N?

N produces x units in ‘t’ M produces x units in ¾ t O produces x units in 3/2t

In 1 minute total units produced by M,N,O working together = 1/t + 4/3t + 2/3t = 3/t Ratio of work done by N in 1 minute = (1/t) / (3/t) = 1/3 This ratio will be the same no matter how long M, N, O work together.

Re: machines m,n,o working simaltaneously [#permalink]

Show Tags

26 Aug 2011, 07:47

1

This post received KUDOS

MBAhereIcome wrote:

Machine M,N,O working simultaneously Machine M can produce x units in 3/4 of the time it takes machine N to produce the same amount of units. Machine N can produce x units in 2/3 the time it takes machine O to produce that amount of units. If all three machines are working simultaneously, what fraction of the total output is produced by machine N?

N produces x units in ‘t’ M produces x units in ¾ t O produces x units in 3/2t

In 1 minute total units produced by M,N,O working together = 1/t + 4/3t + 2/3t = 3/t Ratio of work done by N in 1 minute = (1/t) / (3/t) = 1/3 This ratio will be the same no matter how long M, N, O work together.

Okieee..

Now ultimately the speed of every machine is given with respect to Mach O. So lets assume the speed of O, say 12 hrs to make x units (assuming 6 because we can see we will need to divide by 3 and 4

Mach O makes x units in 12 hrs So, Mach N = 2/3 of O = 2/3*12 = 8 hrs to make x units and Mach M = 3/4 of N = 3/4*8 = 6 hrs to make x units

No they are running simultaneously. Lets see how much each mach makes in 1 hr Mach O = x/12 units Mach N = x/8 units Mach M = x/6 units

In 1 hr, together they make - x/12+x/8+x/6 = 3x/8 So what ratio of this has Mach N made?

(x/8) / (3x/8) = 1/3

Ans: B=1/3 _________________

Happy Learning ! :D

Show Thanks to fellow members with Kudos its shows your appreciation and its free

Re: machines m,n,o working simaltaneously [#permalink]

Show Tags

04 Oct 2011, 12:38

@MBAhereIcome - Kudos to you for this excellent question.

Answer is B. Cheers!
_________________

----------------------------------------------------------------------------------------- What you do TODAY is important because you're exchanging a day of your life for it! -----------------------------------------------------------------------------------------

Re: machines m,n,o working simaltaneously [#permalink]

Show Tags

07 Mar 2012, 09:04

Let O --> T = 12 hours to finish the job Let N --> \(N = \frac{2}{3}*T = 8\) hours the job Let M --> \(M = \frac{3}{4}*\frac{2}{3} * T = 6\) hours to finish the job Combine their rates: \(\frac{1}{6}+\frac{1}{8}+\frac{1}{12} = \frac{3}{8}\) Rate to finish one job together We are looking for the fraction of N on the whole output. Rate of N is \(\frac{1}{8}\), multiply it with the total time of all machines \(*\frac{8}{3} = \frac{1}{3}\)

Machine M,N,O working simultaneously Machine M can produce x units in 3/4 of the time it takes machine N to produce the same amount of units. Machine N can produce x units in 2/3 the time it takes machine O to produce that amount of units. If all three machines are working simultaneously, what fraction of the total output is produced by machine N?

A. 1/2 B. 1/3 C. 4/13 D. 8/29 E. 6/33

Think in terms of ratios for a quick clean solution. Time taken by M : time taken by N = 3:4 So speed of M : speed of N = 4:3 Similarly, speed of N:speed of O = 3:2 Speed of M: Speed of N : Speed of O = 4:3:2 So N will produce 3/(2+3+4) = 1/3rd of the output
_________________

Re: machines m,n,o working simaltaneously [#permalink]

Show Tags

11 Mar 2012, 17:26

I know we are supposed to say thank you by just pressing kudos but I must add here that your methods are very efficient.

VeritasPrepKarishma wrote:

MBAhereIcome wrote:

Machine M,N,O working simultaneously Machine M can produce x units in 3/4 of the time it takes machine N to produce the same amount of units. Machine N can produce x units in 2/3 the time it takes machine O to produce that amount of units. If all three machines are working simultaneously, what fraction of the total output is produced by machine N?

A. 1/2 B. 1/3 C. 4/13 D. 8/29 E. 6/33

Think in terms of ratios for a quick clean solution. Time taken by M : time taken by N = 3:4 So speed of M : speed of N = 4:3 Similarly, speed of N:speed of O = 3:2 Speed of M: Speed of N : Speed of O = 4:3:2 So N will produce 3/(2+3+4) = 1/3rd of the output

Re: Machine M, N, O working simultaneously Machine M can produce [#permalink]

Show Tags

20 Sep 2013, 10:07

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: Machine M, N, O working simultaneously Machine M can produce [#permalink]

Show Tags

14 Mar 2014, 13:59

I would go with smart numbers on this one. Say that N=4, M=3 and O = 6. Therefore all working together will finish x in 4/3 hour. Now in 4/3 hour N does 1/4 so (4/3)(1/4) = 1/3. B is the correct answer

Re: Machine M, N, O working simultaneously Machine M can produce [#permalink]

Show Tags

07 Apr 2015, 09:44

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.
_________________

Hey, guys, So, I’ve decided to run a contest in hopes of getting the word about the site out to as many applicants as possible this application season...

Whether you’re an entrepreneur, aspiring business leader, or you just think that you may want to learn more about business, the thought of getting your Masters in Business Administration...

Whether you’re an entrepreneur, aspiring business leader, or you just think that you may want to learn more about business, the thought of getting your Masters in Business Administration...