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

It is currently 11 Jul 2014, 22:55

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

It takes machine A x hours to manufacture a deck of cards

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 07 Feb 2007
Posts: 54
Location: Philadelphia
Followers: 1

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

It takes machine A x hours to manufacture a deck of cards [#permalink] New post 26 Aug 2007, 19:30
It takes machine A x hours to manufacture a deck of cards that machine B can manufacture in 1/x hours. If machine A operates alone for y hours and is then joined by machine B until 100 decks are finished, for how long will the two machines operate simultaneously?


(100y – x)/(x^2 + 1)

(100x – y)/(x^2 + 1)

(100y – x^3 – x)(x^2 + 1)

(100y – x^2y – y)(x^2 + 1)

100x/(x^2 + 1)

Nice question that I came across. Thought of posting it here. Will post OA later.
Manager
Manager
avatar
Joined: 03 Sep 2006
Posts: 233
Followers: 1

Kudos [?]: 5 [0], given: 0

GMAT Tests User
 [#permalink] New post 27 Aug 2007, 01:00
(1/x)*y + (1/x + x)*Z = 100

[(1 + x^2)/x]*Z = 100 - y/x = (100*x - y)/x

Z = [(100*x - y)/x] / [(1 + x^2)]/x

Z = (100*x - y) / 1 + x^2

P.S> The only thing that we need to understand here is that we should deal with how much work is done by each machine in 1 hour.
CEO
CEO
User avatar
Joined: 29 Mar 2007
Posts: 2593
Followers: 16

Kudos [?]: 173 [0], given: 0

GMAT Tests User
Re: Work Rate problem [#permalink] New post 27 Aug 2007, 15:19
abhi_ferrari wrote:
It takes machine A x hours to manufacture a deck of cards that machine B can manufacture in 1/x hours. If machine A operates alone for y hours and is then joined by machine B until 100 decks are finished, for how long will the two machines operate simultaneously?


(100y – x)/(x^2 + 1)

(100x – y)/(x^2 + 1)

(100y – x^3 – x)(x^2 + 1)

(100y – x^2y – y)(x^2 + 1)

100x/(x^2 + 1)

Nice question that I came across. Thought of posting it here. Will post OA later.


I did VICs prolly not the quickest way since it took me bout 4min :oops:
A B ---> rates will equal A: 1/x B: x
R 1/x x
T x 1/x
D 1 1

For me I couldnt figure out how to do this w/ the variables so...

x=2
y=10hrs

A works for 10 hrs at rate of 1/2 (1 deck every 2hrs) so A makes 5 decks.

now B comes in and there is 95 decks remaining. Find the combined rate

1/x+x/1 or 1/2+2=5/2decks/2hrs. (total rate)

use T=D/R 95/5/2= 38hrs

Ok now is where it begins to take a long time... plug in x and y into the answer choices.

E doesnt work, D is ugly and will take awhile to compute w/ the numbers I chose (come back to this if you exhausted the rest of the answers), C doesnt work,

B works....

A doesnt work. I went w/ B since I was just bought to cross 4min
Re: Work Rate problem   [#permalink] 27 Aug 2007, 15:19
    Similar topics Author Replies Last post
Similar
Topics:
10 Experts publish their posts in the topic Machine A currently takes x hours to complete a certain job. superpus07 22 22 Nov 2012, 12:24
9 Experts publish their posts in the topic It takes machine A 'x' hours to manufacture a deck of cards sjayasa 10 10 Jun 2010, 05:23
It takes machine A x hours to manufacture a deck of cards GMATT73 2 09 Nov 2006, 20:47
It takes machine A x hours to manufacture a deck of cards alimad 2 28 Sep 2006, 16:19
It takes machine A x hours to manufacture a deck of cards cool_jonny009 3 05 Feb 2006, 20:53
Display posts from previous: Sort by

It takes machine A x hours to manufacture a deck of cards

  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®.