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:
Machines X and Y produce bottles at their respective constant rates. [#permalink]
29 Aug 2010, 19:43
1
This post was BOOKMARKED
00:00
A
B
C
D
E
Difficulty:
5% (low)
Question Stats:
85% (02:06) correct
15% (01:37) wrong based on 133 sessions
Machines X and Y produce bottles at their respective constant rates. Machine X produces k bottles in 6 hours and machine Y produces k bottles in 2 hours. How many hours does it take machines X and Y , working simultaneously , to produce 12k bottles?
Re: Machines X and Y produce bottles at their respective constant rates. [#permalink]
31 Aug 2010, 07:26
Machines X and Y produce bottles at their respective constant rates. Machine X produces k bottles in 6 hours and machine Y produces k bottles in 2 hours. How many hours does it take machines X and Y , working simultaneously , to produce 12k bottles?
formula is work = rate x time
for machine (X) k= r X 6 for machine (Y) k= r X 2 now take a value for k ( for ease which is a multiple of both mac X & y) take k=12 so rate of machine (x) is 2 so rate of machine (y) is 6
now work is 12k = 12x12 = 144 two machines working siman so rate = 6+2 =8 work = rate X time 144 = 8 X time so time = 18 so answer D
Re: Machines X and Y produce bottles at their respective constant rates. [#permalink]
20 Feb 2015, 09:34
Safiya wrote:
Machines X and Y produce bottles at their respective constant rates. Machine X produces k bottles in 6 hours and machine Y produces k bottles in 2 hours. How many hours does it take machines X and Y , working simultaneously , to produce 12k bottles?
Re: Machines X and Y produce bottles at their respective constant rates. [#permalink]
20 Feb 2015, 12:30
1
This post received KUDOS
Expert's post
Hi All,
This is an example of a Work Formula question with a minor 'twist.' The "math" in these questions can be done in a few different ways, but since we have 2 machines working on a task together, without any major "twists" (e.g. one of them stops working at a certain point), we can use the Work Formula:
Work = (A)(B)/(A+B) where A and B are the respective rates of the two machines to do the same task individually.
We're told: 1) Machine X can produce K bottles in 6 hours. 2) Machine Y can produce K bottles in 2 hours.
(6)(2)/(6+2) = 12/8 = 1.5 hours to produce K bottles when working together.
The minor 'twist' is that the question asks how long it takes to produce 12K bottles (not K bottles), so we have to multiply this result by 12...
The “3 golden nuggets” of MBA admission process With ten years of experience helping prospective students with MBA admissions and career progression, I will be writing this blog through...
You know what’s worse than getting a ding at one of your dreams schools . Yes its getting that horrid wait-listed email . This limbo is frustrating as hell . Somewhere...