NEW HERE? LEARN MORE
closeclose
Last visit was: 24 Apr 2024, 11:16 It is currently 24 Apr 2024, 11:16
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, machine J, machine K, and machine L can complete a

Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Sajjad1994
GRE Forum Moderator
Joined: 02 Nov 2016
Posts: 13958
Own Kudos [?]: 32881 [6]
Given Kudos: 5776
GPA: 3.62
Send PM
CAT Tests Forum Quiz Mode
Working together, machine J, machine K, and machine L can complete a [#permalink] New post   07 Jun 2021, 21:00
6
Bookmarks
Expert Reply
00:00

Difficulty:

75% (hard)

Question Stats:

55% (03:16) correct 45% (03:20) wrong based on 66 sessions
Hide Show timer Statistics
Working together, machine J, machine K, and machine L can complete a job in 12 minutes. Working alone, machine J can complete a job in 20 minutes. Machine J worked alone for a given amount of time. Then, machines K and L worked together, and with no other machine, for the same amount of time.

In the table below, select two numbers that are consistent with the information that is given. In the first column, select the row that shows the number of jobs completed by machine J working alone, and in the second column, select the row that shows the number of jobs completed by machines K and L working together and with no other machines. Make exactly one selection for each column.
The number of jobs
completed by machine J 		The number of jobs completed by
machines K and L working together
and with no other machines
24
42
60
63
84
96
Submit
Click Submit to add this question to your Error log
ShowHide Answer
Official Answer
The number of jobs
completed by machine J: 63 The number of jobs completed by
machines K and L working together
and with no other machines: 42
User avatar
G
LaveenaPanchal
Manager
Manager
Joined: 06 Oct 2020
Posts: 137
Own Kudos [?]: 108 [3]
Given Kudos: 77
Location: India
Schools: ISB'22
Send PM
Re: Working together, machine J, machine K, and machine L can complete a [#permalink] New post   07 Jun 2021, 21:25
3
Kudos
The Combined rate of J, K, L = 1/12
Rate of Machine J = 1/20. It takes 20 minutes
Rate of K & L = 1/12 - 1/20 = 5/60 - 3/60 = 2/60 = 1/30. K-L take 30 minutes

The time taken is in the rate of 20:30. So the production should also be in the ratio of 3:2.
So the options satisfying this criteria is
The number of jobs completed by machine J - 63
The number of jobs completed by machines K and L working together and with no other machines - 42
User avatar
G
KrishnanTN
Manager
Manager
Joined: 01 Jun 2015
Posts: 81
Own Kudos [?]: 99 [1]
Given Kudos: 108
Location: India
Concentration: General Management, Finance
GMAT 1: 670 Q46 V36
Send PM
Reviews Badge
Re: Working together, machine J, machine K, and machine L can complete a [#permalink] New post   15 Dec 2021, 20:58
1
Kudos
J can complete a piece of work in 20 minutes.
(J + K + L) take 12 minutes to do the same piece of work.
1/12 = 1/20 + (1 / K + 1/L)
--> This implies that (K + L ) can do the work in 30 minutes.

This means that J is more efficient than (K and L) combined.

Now, Since J and (L + K ) worked separately for the same amount of time, multiple the numbers of jobs each by 20 and 30, and choose the options that give the same time as the result.

So, 63 * 20 = 1260
42* 30 = 1260

So, J - 42, (K + L ) = 63
User avatar
B
JoeAa
Manager
Manager
Joined: 09 Aug 2020
Posts: 54
Own Kudos [?]: 9 [0]
Given Kudos: 33
Send PM
Re: Working together, machine J, machine K, and machine L can complete a [#permalink] New post   13 Jan 2024, 11:00
LaveenaPanchal wrote:
The Combined rate of J, K, L = 1/12
Rate of Machine J = 1/20. It takes 20 minutes
Rate of K & L = 1/12 - 1/20 = 5/60 - 3/60 = 2/60 = 1/30. K-L take 30 minutes

The time taken is in the rate of 20:30. So the production should also be in the ratio of 3:2.
So the options satisfying this criteria is
The number of jobs completed by machine J - 63
The number of jobs completed by machines K and L working together and with no other machines - 42


I get the ratio however what's the fastest method by not trial and error one by one, if we only have 2 min per question.
GMAT Club Bot
gmatclubot
Re: Working together, machine J, machine K, and machine L can complete a [#permalink]
13 Jan 2024, 11:00
Moderators:
Bunuel
Math Expert
92902 posts
BottomJee
DI Forum Moderator
1031 posts
chetan2u
RC & DI Moderator
11169 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