GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 15 Nov 2019, 00:07

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.

Close

Request Expert Reply

Confirm Cancel

Roland and Felicia are testing circuit boards for wiring errors. Worki

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 59039
Roland and Felicia are testing circuit boards for wiring errors. Worki  [#permalink]

Show Tags

New post 13 Feb 2019, 00:48
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

87% (01:12) correct 13% (01:52) wrong based on 79 sessions

HideShow timer Statistics

Roland and Felicia are testing circuit boards for wiring errors. Working together, they can test a circuit board in eight minutes. How many circuit boards can Felicia test in an hour
on her own?


(1) Felicia can test circuit boards twice as fast as Roland.

(2) If Roland and Felicia get their friend Cory to help them, they can all work together to test a circuit board in seven minutes.

_________________
GMAT Club Legend
GMAT Club Legend
User avatar
D
Joined: 18 Aug 2017
Posts: 5265
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
GMAT ToolKit User Premium Member CAT Tests
Re: Roland and Felicia are testing circuit boards for wiring errors. Worki  [#permalink]

Show Tags

New post 19 Feb 2019, 05:00
1
Bunuel wrote:
Roland and Felicia are testing circuit boards for wiring errors. Working together, they can test a circuit board in eight minutes. How many circuit boards can Felicia test in an hour
on her own?


(1) Felicia can test circuit boards twice as fast as Roland.

(2) If Roland and Felicia get their friend Cory to help them, they can all work together to test a circuit board in seven minutes.



#1
R+F/RF=1/8
so F=2R
so
3R/2R^2= 1/8
R= 12 mins
sufficient

#2
R+C+F/RCF= 1/7
rate of C and R not known
insuffcient
IMO A
GMAT Club Legend
GMAT Club Legend
User avatar
D
Joined: 18 Aug 2017
Posts: 5265
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
GMAT ToolKit User Premium Member CAT Tests
Re: Roland and Felicia are testing circuit boards for wiring errors. Worki  [#permalink]

Show Tags

New post 07 Mar 2019, 01:52
1
bharat8484 wrote:
can u please explain how did u get 3R/2R^2=1/8....?



bharat8484

Given
let rate of Roland =1/ R and Felicia = 1/F
so time taken by both working together
1/R + 1/F = 1/8
we get
(R+F)/RF=1/8--(1)

#1
given rate of F = 2R
so substitute in (1)
we get
3R/2R^2= 1/8
R= 12 mins
sufficient

Hope this helps.. :)
Intern
Intern
avatar
B
Joined: 25 Nov 2018
Posts: 5
Re: Roland and Felicia are testing circuit boards for wiring errors. Worki  [#permalink]

Show Tags

New post 07 Mar 2019, 01:35
Archit3110 wrote:
Bunuel wrote:
Roland and Felicia are testing circuit boards for wiring errors. Working together, they can test a circuit board in eight minutes. How many circuit boards can Felicia test in an hour
on her own?


(1) Felicia can test circuit boards twice as fast as Roland.

(2) If Roland and Felicia get their friend Cory to help them, they can all work together to test a circuit board in seven minutes.



#1
R+F/RF=1/8
so F=2R
so
3R/2R^2= 1/8
R= 12 mins
sufficient

#2
R+C+F/RCF= 1/7
rate of C and R not known
insuffcient
IMO A
Intern
Intern
avatar
B
Joined: 25 Nov 2018
Posts: 5
Re: Roland and Felicia are testing circuit boards for wiring errors. Worki  [#permalink]

Show Tags

New post 07 Mar 2019, 01:38
can u please explain how did u get 3R/2R^2=1/8....?
Intern
Intern
avatar
B
Joined: 25 Nov 2018
Posts: 5
Re: Roland and Felicia are testing circuit boards for wiring errors. Worki  [#permalink]

Show Tags

New post 07 Mar 2019, 04:32
Archit3110 Oh yes i got it. Thank u so much.. :-)
GMAT Club Bot
Re: Roland and Felicia are testing circuit boards for wiring errors. Worki   [#permalink] 07 Mar 2019, 04:32
Display posts from previous: Sort by

Roland and Felicia are testing circuit boards for wiring errors. Worki

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne