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

It is currently 21 Jul 2018, 10:38

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

Sam and David agreed to complete a work in 14 days.

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

Hide Tags

Manager
Manager
avatar
G
Joined: 20 Feb 2017
Posts: 119
Location: India
Concentration: Operations, Strategy
WE: Engineering (Other)
Sam and David agreed to complete a work in 14 days.  [#permalink]

Show Tags

New post 18 Nov 2017, 23:57
5
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

61% (02:36) correct 39% (02:56) wrong based on 69 sessions

HideShow timer Statistics

Sam and David agreed to complete a work in 14 days. They also agreed to forfeit thrice the amount of wages corresponding to the unfinished if they failed to complete the work in 14 days. As they could not complete the work in 14 days, they lost 3/8th of the amount that they would have together received had they completed the work in time. If Sam alone can complete the work in 80 days,the time that David alone would take to complete the work is

A. 20 days
B. 24 days
C. 30 days
D. 35 days
E. 40 days

self - made Question

_________________

If you feel the post helped you then do send me the kudos (damn theya re more valuable than $)

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 6269
Sam and David agreed to complete a work in 14 days.  [#permalink]

Show Tags

New post 19 Nov 2017, 00:18
1
2
Raksat wrote:
Sam and David agreed to complete a work in 14 days. They also agreed to forfeit thrice the amount of wages corresponding to the unfinished if they failed to complete the work in 14 days. As they could not complete the work in 14 days, they lost 3/8th of the amount that they would have together received had they completed the work in time. If Sam alone can complete the work in 80 days,the time that David alone would take to complete the work is

A. 20 days
B. 24 days
C. 30 days
D. 35 days
E. 40 days

self - made Question



hi...

you would see such Q more frequently in CAT

but let's solve it.

they were to lose thrice the amount of wages of work that was left ....
so if they lost \(\frac{3}{8}\) of work, they did not do \(\frac{3}{8} * \frac{1}{3} = \frac{1}{8}\) of work

In other words they did only \(1-\frac{1}{8} = \frac{7}{8}\) of work
if they do 7/8 of work in 14 days, they will do complete job in 14*8/7 = 16 days..

David's one day work = \(\frac{1}{16}-\frac{1}{80} = \frac{5-1}{80}=\frac{4}{80}=\frac{1}{20}\)
so david does it in 20 days

A
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

Manager
Manager
avatar
G
Joined: 20 Feb 2017
Posts: 119
Location: India
Concentration: Operations, Strategy
WE: Engineering (Other)
Re: Sam and David agreed to complete a work in 14 days.  [#permalink]

Show Tags

New post 19 Nov 2017, 00:23
chetan2u wrote:
Raksat wrote:
Sam and David agreed to complete a work in 14 days. They also agreed to forfeit thrice the amount of wages corresponding to the unfinished if they failed to complete the work in 14 days. As they could not complete the work in 14 days, they lost 3/8th of the amount that they would have together received had they completed the work in time. If Sam alone can complete the work in 80 days,the time that David alone would take to complete the work is

A. 20 days
B. 24 days
C. 30 days
D. 35 days
E. 40 days

self - made Question



hi...

you would see such Q more frequently in CAT

but let's solve it.

they were to lose thrice the amount of wages of work that was left ....
so if they lost \(\frac{3}{8}\) of work, they did not do \(\frac{3}{8} * \frac{1}{3} = \frac{1}{8}\) of work

In other words they did only \(1-\frac{1}{8} = \frac{7}{8}\) of work
if they do 7/8 of work in 14 days, they will do complete job in 14*8/7 = 16 days..

David's one day work = \(\frac{1}{16}-\frac{1}{80} = \frac{5-1}{80}=\frac{4}{80}=\frac{1}{20}\)
so david does it in 20 days

A

Is there any method apart from UNITARY METHOD. Normally i take LCM and try to solve but some questions couldn't be solved using this method. And i couldn't grasp unitary method completely. Upto 700 level questions its fine but beyond 700 , it becomes a strech.
_________________

If you feel the post helped you then do send me the kudos (damn theya re more valuable than $)

Expert Post
Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2679
Re: Sam and David agreed to complete a work in 14 days.  [#permalink]

Show Tags

New post 22 Nov 2017, 13:20
Raksat wrote:
Sam and David agreed to complete a work in 14 days. They also agreed to forfeit thrice the amount of wages corresponding to the unfinished if they failed to complete the work in 14 days. As they could not complete the work in 14 days, they lost 3/8th of the amount that they would have together received had they completed the work in time. If Sam alone can complete the work in 80 days,the time that David alone would take to complete the work is

A. 20 days
B. 24 days
C. 30 days
D. 35 days
E. 40 days


Since they lost 3/8 of the amount that they would have together received had they completed the job on time and they actually forfeited thrice the amount of wages corresponding to the unfinished, we can relate these two quantities as: ⅜ = 3x, and so x = ⅛, which means that they only had 1/8 of the job unfinished. In other words, they finished 7/8 of the job.

We can let n = the number of days David would take to complete the work alone. We are given that Sam would take 80 days to complete the work alone; thus, his rate would be 1/80, and David’s rate would be 1/n. Since they both worked 14 days, and they finished 7/8 of the job, we can create the following equation:

14 x 1/80 + 14 x 1/n = 7/8

14/80 + 14/n = 7/8

Multiply the equation by 80n we have:

14n + 1120 = 70n

1120 = 56n

n = 1120/56 = 20

Answer: A
_________________

Jeffery Miller
Head of GMAT Instruction

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Senior Manager
Senior Manager
avatar
G
Joined: 02 Apr 2014
Posts: 486
GMAT 1: 700 Q50 V34
Re: Sam and David agreed to complete a work in 14 days.  [#permalink]

Show Tags

New post 23 Feb 2018, 10:48
chetan2u wrote:
Raksat wrote:
Sam and David agreed to complete a work in 14 days. They also agreed to forfeit thrice the amount of wages corresponding to the unfinished if they failed to complete the work in 14 days. As they could not complete the work in 14 days, they lost 3/8th of the amount that they would have together received had they completed the work in time. If Sam alone can complete the work in 80 days,the time that David alone would take to complete the work is

A. 20 days
B. 24 days
C. 30 days
D. 35 days
E. 40 days

self - made Question



hi...

you would see such Q more frequently in CAT

but let's solve it.

they were to lose thrice the amount of wages of work that was left ....
so if they lost \(\frac{3}{8}\) of work, they did not do \(\frac{3}{8} * \frac{1}{3} = \frac{1}{8}\) of work

In other words they did only \(1-\frac{1}{8} = \frac{7}{8}\) of work
if they do 7/8 of work in 14 days, they will do complete job in 14*8/7 = 16 days..

David's one day work = \(\frac{1}{16}-\frac{1}{80} = \frac{5-1}{80}=\frac{4}{80}=\frac{1}{20}\)
so david does it in 20 days

A


Hi chetan2u, CAT - are you referring to IIM CAT exams?

Thanks
Re: Sam and David agreed to complete a work in 14 days. &nbs [#permalink] 23 Feb 2018, 10:48
Display posts from previous: Sort by

Sam and David agreed to complete a work in 14 days.

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

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.