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

It is currently 07 Jul 2015, 18:17

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

Work Rate Questions - I collected from GMAT Club

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 24 Oct 2011
Posts: 95
Location: India
Concentration: General Management, International Business
GMAT Date: 11-29-2011
GPA: 3.5
WE: Web Development (Computer Software)
Followers: 1

Kudos [?]: 16 [0], given: 27

Re: Work Rate Questions - I collected from GMAT Club [#permalink] New post 03 Dec 2011, 10:11
Thnx for questions and answers.. Really helpful
Director
Director
User avatar
Status: No dream is too large, no dreamer is too small
Joined: 14 Jul 2010
Posts: 660
Followers: 37

Kudos [?]: 387 [0], given: 39

Re: Work Rate Questions - I collected from GMAT Club [#permalink] New post 17 Dec 2011, 13:39
Ans. of 14 is 6. not 1.
Joint Rate of John and Jane= 1/20+1/12 = 2/15

John does in 4 days = 1/20*4= 1/5
left 4/5 part is done by both them.

So together they work = 4/5*15/2 = 6 Ans.
_________________

Collections:-
PSof OG solved by GC members: http://gmatclub.com/forum/collection-ps-with-solution-from-gmatclub-110005.html
DS of OG solved by GC members: http://gmatclub.com/forum/collection-ds-with-solution-from-gmatclub-110004.html
100 GMAT PREP Quantitative collection http://gmatclub.com/forum/gmat-prep-problem-collections-114358.html
Collections of work/rate problems with solutions http://gmatclub.com/forum/collections-of-work-rate-problem-with-solutions-118919.html
Mixture problems in a file with best solutions: http://gmatclub.com/forum/mixture-problems-with-best-and-easy-solutions-all-together-124644.html

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 5402
Followers: 311

Kudos [?]: 60 [0], given: 0

Premium Member
Re: Work Rate Questions - I collected from GMAT Club [#permalink] New post 22 Jul 2014, 03:55
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

Senior Manager
Senior Manager
User avatar
Status: Math is psycho-logical
Joined: 07 Apr 2014
Posts: 408
Location: Netherlands
GMAT Date: 02-11-2015
WE: Psychology and Counseling (Other)
Followers: 1

Kudos [?]: 54 [0], given: 148

Re: Work Rate Questions - I collected from GMAT Club [#permalink] New post 28 Dec 2014, 05:23
For Q8 there is an easy approach to think about it. This is actually thw working together scenario, with one twist.
So, when machines work together, you add their individual rates to find the average rate. When one is undoing the work of the other what you do is subtract the rates. In the RT=W chart, we fill in the info we know:

R T W
Filling valve 1/4 10 1
Draining valve 1/5 x 1

Now, the chart is creating an equation, but we need to pay attention to subtract the rates instead of adding them:
(1/4)*10 - (1/5)x = 1
(50-4x)/20=1
50-4x=20
4x=30
x=7.5

Looking at the chart, x is the time the draining valve was working. So, from the time it took to fill the whole pool we subtract the time the draining valve was working: 23-7.5= 15.5 or 3.30 | 11-7.5=3.5 if you prefer, which in terms of time is 3 hours plus half an hour which is 3.30.
Intern
Intern
avatar
Joined: 27 Dec 2014
Posts: 4
Followers: 0

Kudos [?]: 0 [0], given: 17

Re: Work Rate Questions - I collected from GMAT Club [#permalink] New post 06 Feb 2015, 02:39
solution for number 2 : E (12 )

R * T = W
for machine y : 1 /t * t =1
for machine x : 1 / (t+2) * (t+2) =1
both together : 5 /12 * 12/5 = 1 ( calculated the rate 5/12 from the given information)

the single rates are together the combined rate.
( 1/t + 1/(t+2)) = 5/12
solving for t (using pq formula).

t = 4 (second solution is negative, not relevant )

how many days does machine x need to produce 2 w? We know know the rate of machine x ( 1/(t+2) = 1 /(2+4)

1 /6 * x = 2
Solved, x= 12

Machine x needs 12 days to produce 2 widgets.
Re: Work Rate Questions - I collected from GMAT Club   [#permalink] 06 Feb 2015, 02:39

Go to page   Previous    1   2   [ 25 posts ] 

    Similar topics Author Replies Last post
Similar
Topics:
33 Collections of work/rate problem with solutions Baten80 14 14 Aug 2011, 11:49
3 Experts publish their posts in the topic Problems with Work/Rate questions marijose 8 11 Feb 2011, 07:20
1 Work and Rate GMAT Questions - Word Problems Master List timetrader 4 17 Jun 2009, 06:25
31 Experts publish their posts in the topic Collection of work/rate problems? Economist 111 27 Mar 2009, 23:15
Here is my collection of Quant questions from the 4GMAT.com yessuresh 8 14 Sep 2006, 19:11
Display posts from previous: Sort by

Work Rate Questions - I collected from GMAT Club

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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®.