NEW HERE? LEARN MORE
closeclose
Last visit was: 23 Apr 2024, 20:53 It is currently 23 Apr 2024, 20:53
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

Machines A, B, and C can either load nails into a bin or unload nails

User avatar
kirankp
Manager
Manager
Joined: 22 Jul 2008
Posts: 58
Own Kudos [?]: 1053 [0]
Given Kudos: 11
Location: Bangalore,Karnataka
Send PM
Machines A, B, and C can either load nails into a bin or unload nails [#permalink] New post   Updated on: 30 Nov 2009, 09:01
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

94% (02:12) correct 6% (02:11) wrong based on 124 sessions
Hide Show timer Statistics
Machines A, B, and C can either load nails into a bin or unload nails from that bin. Each machine works at a constant rate that is the same for loading and for unloading, although the individual machines may have different rates. Working together to load at their respective constant rates, machines A and B can load the bin in 6 minutes. Likewise, working together to load at their respective constant rates, machines B and C can load the bin in 9 minutes. How long will it take machine A to load the bin if machine C is simultaneously unloading the bin?

(A) 12 minutes
(B) 15 minutes
(C) 18 minutes
(D) 36 minutes
(E) 54 minutes

OPE DISCUSSION OF THIS QUESTION IS HERE: machines-a-b-and-c-can-either-load-nails-into-a-bin-or-86031.html

Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!

Originally posted by kirankp on 30 Nov 2009, 07:57.
Last edited by kirankp on 30 Nov 2009, 09:01, edited 1 time in total.
User avatar
lagomez
VP
VP
Joined: 05 Mar 2008
Posts: 1226
Own Kudos [?]: 517 [2]
Given Kudos: 31
Send PM
Re: Machines A, B, and C can either load nails into a bin or unload nails [#permalink] New post   30 Nov 2009, 08:18
1
Kudos
1
Bookmarks
kirankp wrote:
I guess a similar question was posted by Bunel sometime back.. anyhow here it is

Machines A, B, and C can either load nails into a bin or unload nails from that bin. Each machine works at a constant rate that is the same for loading and for unloading, although the individual machines may have different rates. Working together to load at their respective constant rates, machines A and B can load the bin in 6 minutes. Likewise, working together to load at their respective constant rates, machines B and C can load the bin in 9 minutes. How long will it take machine A to load the bin if machine C is simultaneously unloading the bin?
(A) 12 minutes
(B) 15 minutes
(C) 18 minutes
(D) 36 minutes
(E) 54 minutes


answer C

A and B together = 1/a + 1/b = 1/6

B and C together = 1/b + 1/c = 1/9

We need to know the answer to 1/a - 1/c

From equation 2: 1/b = 1/9 - 1/c
substitute into equation 1

1/a + 1/9 - 1/c = 1/6
1/a - 1/c = 1/18

18 minutes
User avatar
mejia401
Senior Manager
Senior Manager
Joined: 15 Sep 2011
Posts: 258
Own Kudos [?]: 1370 [1]
Given Kudos: 46
Location: United States
WE:Corporate Finance (Manufacturing)
Send PM
GMAT ToolKit User
Re: Machines A, B, and C can either load nails into a bin or unload nails [#permalink] New post   25 Jun 2015, 08:42
1
Kudos
kirankp wrote:
I guess a similar question was posted by Bunuel sometime back.. anyhow here it is

Machines A, B, and C can either load nails into a bin or unload nails from that bin. Each machine works at a constant rate that is the same for loading and for unloading, although the individual machines may have different rates. Working together to load at their respective constant rates, machines A and B can load the bin in 6 minutes. Likewise, working together to load at their respective constant rates, machines B and C can load the bin in 9 minutes. How long will it take machine A to load the bin if machine C is simultaneously unloading the bin?
(A) 12 minutes
(B) 15 minutes
(C) 18 minutes
(D) 36 minutes
(E) 54 minutes


Bumping up. Moderator should edit in answer.
\(\frac{1}{6}\) - \(\frac{1}{9}\) = \(\frac{1}{18}\)
D. 18 minutes.

This works because \(\frac{a+b}{ab}\) - \(\frac{b+c}{bc}\) = \(\frac{c-a}{ac}\) and \(\frac{1}{a}\) - \(\frac{1}{c}\) = \(\frac{c-a}{ac}\)
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92883
Own Kudos [?]: 618619 [0]
Given Kudos: 81563
Send PM
CAT Tests Forum Quiz Mode
Re: Machines A, B, and C can either load nails into a bin or unload nails [#permalink] New post   25 Jun 2015, 08:47
Expert Reply
OPE DISCUSSION OF THIS QUESTION IS HERE: machines-a-b-and-c-can-either-load-nails-into-a-bin-or-86031.html
User avatar
L
chetan2u
RC & DI Moderator
Joined: 02 Aug 2009
Status:Math and DI Expert
Posts: 11161
Own Kudos [?]: 31870 [0]
Given Kudos: 290
Send PM
Reviews Badge
Re: Machines A, B, and C can either load nails into a bin or unload nails [#permalink] New post   25 Jun 2015, 08:49
Expert Reply
mejia401 wrote:
kirankp wrote:
I guess a similar question was posted by Bunuel sometime back.. anyhow here it is

Machines A, B, and C can either load nails into a bin or unload nails from that bin. Each machine works at a constant rate that is the same for loading and for unloading, although the individual machines may have different rates. Working together to load at their respective constant rates, machines A and B can load the bin in 6 minutes. Likewise, working together to load at their respective constant rates, machines B and C can load the bin in 9 minutes. How long will it take machine A to load the bin if machine C is simultaneously unloading the bin?
(A) 12 minutes
(B) 15 minutes
(C) 18 minutes
(D) 36 minutes
(E) 54 minutes


Bumping up. Moderator should edit in answer.
\(\frac{1}{6}\) - \(\frac{1}{9}\) = \(\frac{1}{18}\)
D. 18 minutes.

This works because \(\frac{a+b}{ab}\) - \(\frac{b+c}{bc}\) = \(\frac{c-a}{ac}\) and \(\frac{1}{a}\) - \(\frac{1}{c}\) = \(\frac{c-a}{ac}\)


Ans is ok as it is it is C which is 18 and D is 36...

Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
gmatclubot
Re: Machines A, B, and C can either load nails into a bin or unload nails [#permalink]
25 Jun 2015, 08:49
Moderators:
Bunuel
Math Expert
92883 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions