Last visit was: 23 Apr 2026, 03:02 It is currently 23 Apr 2026, 03:02
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
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 23 Apr 2026
Posts: 109,771
Own Kudos:
810,727
 [1]
Given Kudos: 105,853
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,771
Kudos: 810,727
 [1]
How long would it take Joan to count the books in a small library? 24 Jan 2016, 05:37
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

5% (low)

Question Stats:

89% (00:37) correct 11% (00:53) wrong based on 150 sessions

History

Date
Time
Result
Not Attempted Yet
How long would it take Joan to count the books in a small library?

(1) She counts twice as fast as Emily.
(2) Working together, Joan and Emily count the books in 26 hours.
ShowHide Answer
Official Answer
C
avatar
saiesta
avatar
Joined: 03 Jan 2015
Last visit: 15 Nov 2018
Posts: 59
Own Kudos:
320
Given Kudos: 146
Posts: 59
Kudos: 320
How long would it take Joan to count the books in a small library? 24 Jan 2016, 14:06
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I believe answer C.


(1) She counts twice as fast as Emily.
J = 2E. Not sufficient
(2) Working together, Joan and Emily count the books in 26 hours.
J + E = 26. Not sufficient

Together, you can solve for J. Answer choice C.
User avatar
Mo2men
User avatar
Joined: 26 Mar 2013
Last visit: 09 May 2023
Posts: 2,426
Own Kudos:
1,508
Given Kudos: 641
Concentration: Operations, Strategy
Schools: Erasmus (II)
Products:
My Reviews
Schools: Erasmus (II)
Posts: 2,426
Kudos: 1,508
How long would it take Joan to count the books in a small library? 25 Jan 2016, 01:38
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
How long would it take Joan to count the books in a small library?

(1) She counts twice as fast as Emily.
(2) Working together, Joan and Emily count the books in 26 hours.
Show more

combines Rate (R) = RJ + RE; RJ=Joan rate & RE=Emily rate

1) RJ=2RE ......Ins

2)Combines Rate= 1/26....ins

Combined 1& 2

RJ+RE=1/26....> 1/26= RJ+ 1/2 (RE)..............Suf

Answer: C
User avatar
Kingsman
User avatar
Joined: 11 Jan 2014
Last visit: 28 Apr 2019
Posts: 23
Own Kudos:
27
Given Kudos: 58
Location: Viet Nam
Concentration: Accounting, Finance
GPA: 3.17
WE:Analyst (Accounting)
Posts: 23
Kudos: 27
How long would it take Joan to count the books in a small library? 25 Jan 2016, 13:33
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
How long would it take Joan to count the books in a small library?

(1) She counts twice as fast as Emily.
(2) Working together, Joan and Emily count the books in 26 hours.
Show more

One C for me.
(1) We did not know how long Emily took to count the books in the lib --> insufficient.
(2) We did not know the rate between Emily and Joan in counting the books--> insufficient.
(1) & (2)--> support to each other
avatar
ZaydenBond
avatar
Joined: 22 Oct 2015
Last visit: 19 Feb 2017
Posts: 9
Own Kudos:
7
 [1]
Given Kudos: 4
Posts: 9
Kudos: 7
 [1]
How long would it take Joan to count the books in a small library? 04 Feb 2016, 10:35
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
I am really bad at these sorts of problems so could someone check to see if this is correct?

Given that I understand that both statements together are sufficient, is the math correct?

1. She counts twice as fast as Emily.
Joans rate is \(\frac{1}{x}\) and Emilys rate is \(\frac{1}{x}*\frac{1}{2}\) because it is half of Joans

2.Working together, Joan and Emily count the books in 26 hours.

\(\frac{1}{26}=\frac{1}{x}+\frac{1}{2x}\)
\(\frac{1}{26}=\frac{3}{2x}\)
\(78=2x\)
\(x=39\)

Joans rate is \(\frac{1}{39}\) and Emilys rate is \(\frac{1}{78}\)
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,959
Own Kudos:
1,117
Posts: 38,959
Kudos: 1,117
How long would it take Joan to count the books in a small library? 17 Oct 2018, 10:25
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
109766 posts
kingbucky
498 posts
Gmat860sanskar
212 posts