Last visit was: 21 Apr 2026, 05:15 It is currently 21 Apr 2026, 05:15
Home
Messages
Tests
Schools
Events
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
Back to Forum
Create Topic
User avatar
Jihyo
User avatar
Joined: 01 Apr 2021
Last visit: 06 Mar 2022
Posts: 53
Own Kudos:
220
 [22]
Given Kudos: 166
Posts: 53
Kudos: 220
 [22]
Ruby takes 2 days more than what Alia takes to produce x chairs 24 Apr 2021, 03:37
2
Kudos
Add Kudos
20
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

95% (hard)

Question Stats:

43% (02:57) correct 57% (03:05) wrong based on 108 sessions

History

Date
Time
Result
Not Attempted Yet
Ruby takes 2 days more than what Alia takes to produce x chairs. They work together for 6 days and produce 24x chairs.How many days will it take Ruby to produce 2x chairs?
A)2
B)4
C)5
D)6
E)None of these
ShowHide Answer
Official Answer
E
Most Helpful Reply
User avatar
globaldesi
User avatar
Joined: 28 Jul 2016
Last visit: 23 Feb 2026
Posts: 1,141
Own Kudos:
1,995
 [11]
Given Kudos: 67
Location: India
Concentration: Finance, Human Resources
Schools: ISB '18 (D)
GPA: 3.97
WE:Project Management (Finance: Investment Banking)
Products:
My Reviews
Schools: ISB '18 (D)
Posts: 1,141
Kudos: 1,995
 [11]
Ruby takes 2 days more than what Alia takes to produce x chairs 24 Apr 2021, 07:51
8
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
Jihyo
Can you post official explanation please
according to me let the number of days taken by Alia be d hence ruby takes d+2 days
so
total work done in 6 days =\( 6(\frac{x}{d})+6(\frac{x}{d+2}) = 24x\)

solving for d we get d = -7/4 or 1/4
days cant be negative
so d = 1/4
hence ruby takes 2.25 days to make x xhaires
she would take 2.25*2 days = 4.5 days
General Discussion
User avatar
RajatJ79
User avatar
Joined: 06 Oct 2019
Last visit: 03 Dec 2023
Posts: 132
Own Kudos:
204
Given Kudos: 242
Concentration: Strategy, Technology
WE:Marketing (Internet and New Media)
Posts: 132
Kudos: 204
Ruby takes 2 days more than what Alia takes to produce x chairs 24 Apr 2021, 08:29
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Jihyo - request you to post the official explaination please

Posted from my mobile device
User avatar
Jihyo
User avatar
Joined: 01 Apr 2021
Last visit: 06 Mar 2022
Posts: 53
Own Kudos:
220
 [2]
Given Kudos: 166
Posts: 53
Kudos: 220
 [2]
Ruby takes 2 days more than what Alia takes to produce x chairs 24 Apr 2021, 08:59
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
OFFICIAL ANSWER

They have to work together for 6 days to produce 24x chairs
So,they have to work together for 1 day to produce 4x chair(unitary method)......(1)
Ruby takes 2 more days to produce x chairs than Alia does
So,if Alia produces x chair in y days,Ruby produces x chair in (y+2) days
In y days , Alia produces x chairs ,so in 1 day , Alia produces x/y chair
In y+2 days ,Ruby produces x chair,so in 1 day ,Ruby produces x/(y+2) chair
So ,together in 1 day they produce x/y+x/(x+y) chair ....(2)
combining (1) and (2),
x/y+x/(x+y)=4x
=>4xy^2+6xy-2x=0
=>2y^2+3y-1=0
solving the equation with quadratic formula
x=(−b±\sqrt{b2−4ac})/(2a) we get,
y=-3±\sqrt{18}/4
By taking only the positive values ,we get the value of y to be an irrational number.So,the number of days Ruby needs to prepare 2x chair is also a irrational figure,which is not in the options.

ANSWER: E) None of these
User avatar
chetan2u
User avatar
GMAT Expert
Joined: 02 Aug 2009
Last visit: 18 Apr 2026
Posts: 11,230
Own Kudos:
44,981
 [1]
Given Kudos: 335
Status:Math and DI Expert
Location: India
Concentration: Human Resources, General Management
GMAT Focus 1: 735 Q90 V89 DI81
Products:
My Reviews
Expert
Expert reply
GMAT Focus 1: 735 Q90 V89 DI81
Posts: 11,230
Kudos: 44,981
 [1]
Ruby takes 2 days more than what Alia takes to produce x chairs 04 May 2021, 11:06
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Jihyo
Ruby takes 2 days more than what Alia takes to produce x chairs. They work together for 6 days and produce 24x chairs.How many days will it take Ruby to produce 2x chairs?
A)2
B)4
C)5
D)6
E)None of these
Show more


Both work together for 6 days to produce 24x chairs.
This means both can produce x chairs in 6/24 or 1/4 day.

Let Alina take a days, so Ruby will take a+2 days to make x chairs.

\(\frac{1}{a}+\frac{1}{a+2}=4\)

\(a+2+a=4*a(a+2).......2a+2=4a^2+8a......4a^2+6a-2=0.....2a^2+3a-1=0\)
a=0.28 approx

So a+2=2.28


So Ruby takes 2.28 days for x chairs and will take 2*2.28=4.56 days for 2x chairs.

Of course it would have been better if the question had more friendly numbers.
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,944
Own Kudos:
1,116
Posts: 38,944
Kudos: 1,116
Ruby takes 2 days more than what Alia takes to produce x chairs 29 Oct 2025, 09:40
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Bunuel
Math Expert
109720 posts
Krunaal
Tuck School Moderator
853 posts