NEW HERE? LEARN MORE
closeclose
Last visit was: 28 Apr 2024, 13:54 It is currently 28 Apr 2024, 13:54
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

Working together without taking breaks, Michael and Donna painted the

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92977
Own Kudos [?]: 619704 [3]
Given Kudos: 81613
Send PM
CAT Tests Forum Quiz Mode
Working together without taking breaks, Michael and Donna painted the [#permalink] New post   16 May 2023, 01:30
3
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

5% (low)

Question Stats:

84% (01:23) correct 16% (02:01) wrong based on 88 sessions
Hide Show timer Statistics
Working together without taking breaks, Michael and Donna painted the sidewalk in 6 hours. How long would it take Michael to paint the sidewalk by himself?

(1) If Michael had left when the job was 1/3 done, it would have taken Donna 8 hours to finish the job by herself.

(2) If Donna had to paint 2 identical sidewalks all by herself, it would have taken her 24 hours to finish.


ShowHide Answer
Official Answer
D
User avatar
S
chanhthang1802
Manager
Manager
Joined: 17 Aug 2020
Posts: 62
Own Kudos [?]: 54 [1]
Given Kudos: 15
Location: Germany
GMAT 1: 760 Q50 V42
GPA: 3.49
Send PM
Reviews Badge
Re: Working together without taking breaks, Michael and Donna painted the [#permalink] New post   16 May 2023, 05:08
1
Kudos
Let the time it takes for Michael or Donna alone to complete the sidewalk be M and D, respectively. We have 1/M + 1/D = 1/6
Question: M = ?
(1) Michael had left when the job was 1/3 done means that Michael and Donna have worked together for 1/3 of the job.
It takes Donna 8 hours to finish 2/3 of the job --> D = 8*3/2 = 12 hours
--> 1/M + 1/12 = 1/6 --> M = 12 --> sufficient
(2) 2D = 24 --> D = 12 --> Same as (1) --> sufficient
Therefore (D) is the answer.
User avatar
S
TheBipedalHorse
Manager
Manager
Joined: 16 Jun 2021
Posts: 110
Own Kudos [?]: 29 [1]
Given Kudos: 98
Send PM
Re: Working together without taking breaks, Michael and Donna painted the [#permalink] New post   16 May 2023, 10:02
1
Kudos
Working together without taking breaks, Michael and Donna painted the sidewalk in 6 hours. How long would it take Michael to paint the sidewalk by himself?

(1) If Michael had left when the job was 1/3 done, it would have taken Donna 8 hours to finish the job by herself.
Donna finishes 2/3 job in 8 hours. Therefore it takes her 12 hours to finish the job alone and therefore it also takes Michael 12 hours to finish the job, only then can the both of them finish the entire job in 6 hours

Therefore 1 alone is enough

(2) If Donna had to paint 2 identical sidewalks all by herself, it would have taken her 24 hours to finish.
To paint one wall, it would take her 12 hours, and again by the same logic, it takes Michael 12 hours also to finish the job

Therefore 2 alone is enough

Therefore each statement alone is enough
User avatar
G
RICHA1189
Manager
Manager
Joined: 02 Dec 2022
Posts: 181
Own Kudos [?]: 71 [1]
Given Kudos: 342
Send PM
Re: Working together without taking breaks, Michael and Donna painted the [#permalink] New post   16 May 2023, 10:29
1
Kudos
Working together without taking breaks, Michael and Donna painted the sidewalk in 6 hours. How long would it take Michael to paint the sidewalk by himself?

Let work done by Michael be M and Donna be D
GIVEN : 1/M + 1/D = 1/6
If we get the rate of Donna , we will be able to find one unique value M


(1) If Michael had left when the job was 1/3 done, it would have taken Donna 8 hours to finish the job by herself.

This statement implies that DONNA does 2/3rd of the work in 8 hrs
I.E. 1 work in 8*3/2 hrs = 12 hrs
We have got value of D , We can find the value of M . On solving we get the value of M = 12 hrs

Sufficient A/D

(2) If Donna had to paint 2 identical sidewalks all by herself, it would have taken her 24 hours to finish.

2 identical sidewalks 24 hrs , I.e. 1 sidewalk in 12 hrs
Equation is same as statement 1
Sufficient

Answer is D
GMAT Club Bot
gmatclubot
Re: Working together without taking breaks, Michael and Donna painted the [#permalink]
16 May 2023, 10:29
Moderator:
Bunuel
Math Expert
92977 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