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

It is currently 23 Jul 2014, 08:20

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

Six machines, each working at the same constant rate,

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 05 Jan 2006
Posts: 66
Followers: 1

Kudos [?]: 4 [0], given: 0

Six machines, each working at the same constant rate, [#permalink] New post 21 May 2006, 13:51
Six machines, each working at the same constant rate, together can complete a certain job in 12 days. How many additional machines, each working at the same constant rate, will be needed to complete the job in 8 days?

(A) 2
(B) 3
(C) 4
(D) 6
(E) 8

Please explain.
Director
Director
avatar
Joined: 24 Oct 2005
Posts: 662
Location: London
Followers: 1

Kudos [?]: 6 [0], given: 0

GMAT Tests User
 [#permalink] New post 21 May 2006, 13:56
6 machines - 12 days.
Therefore 1 machine = 12*6 days.
8 days - (12*6)/8 = 9 machines.

No of addn machines = 9-6 = 3

Ans = B
Senior Manager
Senior Manager
avatar
Joined: 15 Mar 2005
Posts: 425
Location: Phoenix
Followers: 1

Kudos [?]: 9 [0], given: 0

GMAT Tests User
Re: Another rate question [#permalink] New post 21 May 2006, 16:51
x242222 wrote:
Six machines, each working at the same constant rate, together can complete a certain job in 12 days. How many additional machines, each working at the same constant rate, will be needed to complete the job in 8 days?

(A) 2
(B) 3
(C) 4
(D) 6
(E) 8

Please explain.

Another way:
12 days -> 8 days => Machines = 6*12/8 = 9. Thus additional machines = 3.

_________________

Who says elephants can't dance?

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jul 2004
Posts: 5097
Location: Singapore
Followers: 16

Kudos [?]: 131 [0], given: 0

GMAT Tests User
 [#permalink] New post 21 May 2006, 21:41
Rate of each machine: 1 job in a hours, so 1/a job in 1 hour

Working together, 6/a job in 1 hour. So 1 job will take a/6 hours

a/6 = 12*24
a = 1728 hours

Assume we need n such machines

n/a job in 1 hour --> 1 job in a/n hours

1827/n = 8 * 24 =

n = 9

# of additional machines = 3
  [#permalink] 21 May 2006, 21:41
    Similar topics Author Replies Last post
Similar
Topics:
8 Experts publish their posts in the topic Six machines, each working at the same constant rate zz0vlb 16 26 Apr 2010, 20:53
Six machines, each working at the same constant rate, above720 1 09 Feb 2007, 20:43
Six machines, each working at the same constant rate, jayy178 4 19 Nov 2006, 22:09
Six machines, each working at the same constant rate, uphillclimb 6 21 Oct 2006, 09:45
Six machines, each working at the same constant rate, Matador 10 06 Apr 2006, 14:24
Display posts from previous: Sort by

Six machines, each working at the same constant rate,

  Question banks Downloads My Bookmarks Reviews Important topics  


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®.