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

It is currently 02 Oct 2014, 05:21

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

Running at their respective constant rates, machine X takes

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 12 Aug 2004
Posts: 10
Followers: 0

Kudos [?]: 3 [0], given: 0

Running at their respective constant rates, machine X takes [#permalink] New post 05 Nov 2004, 23:42
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

100% (05:25) correct 0% (00:00) wrong based on 3 sessions
Running at their respective constant rates, machine X takes 2 days longer to produce w widgets than machine Y. At these rates, if the two machines together produce 5/4 w widgets in 3 days, how many days would it take machine X alone to produce 2w widgets?
A) 4
B) 6
C) 8
D) 10
E) 12

Please explain your answer. Thank you.
Director
Director
User avatar
Joined: 16 Jun 2004
Posts: 893
Followers: 1

Kudos [?]: 10 [0], given: 0

 [#permalink] New post 06 Nov 2004, 00:06
I am getting 12. E. Hope havent done any calculation errors..

approach..
let y=no. of days taken by Y to do w widgets. Then X will take y+2 days.

1/(y+2) +1/y = 5/12 (5/12 is because (5/4)w widgets are done in 3 days. So, x widgets will be done in 12/5 days or 5/12 th of a widget in a day)

Solving, we have y = 4

=>X takes 6 days to doing x widgets. So, he will take 12 days to doing 2w widgets.
Intern
Intern
avatar
Joined: 25 Oct 2004
Posts: 7
Followers: 0

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

 [#permalink] New post 06 Nov 2004, 04:32
I also get 12 (E).

My approach was a little more complicated.

Work formula : COMBINED TIME =(A*B) : (A+B) , where A- time for 1st machine , B - time for 2nd machine.

(2+z) days will take machine A to produce 1 widg. and
z days will take machine to produce 1 widg.

Thus, (z*(z+2)) : (z+z+2)*5/4 =3 (days)

5z^2 +10z - 24 =0

z=4 ; z=-1,2 ( negative is not appropriate so we rid of it )

Consequently,machine A takes (2+z)days = 2+4= 6 (days to produce one widg.); and (6*2) = 12 (days to produce two widg.).

B/R
Oh Gal Len
  [#permalink] 06 Nov 2004, 04:32
    Similar topics Author Replies Last post
Similar
Topics:
Running at their respective constant rates, machine X takes alohagirl 2 03 Nov 2007, 08:32
Running at their respective constant rates, machine X takes gluon 7 22 Sep 2007, 06:52
Running at their respective constant rates, machine X takes solidcolor 5 30 Aug 2007, 19:37
Running at their respective constant rates, machine X takes Iawfy 2 29 Dec 2006, 18:51
Running at their respective constant rates, machine X takes joemama142000 3 06 Feb 2006, 21:56
Display posts from previous: Sort by

Running at their respective constant rates, machine X takes

  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®.