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

It is currently 18 Jul 2018, 09:34

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

A contractor undertakes to do a job within 20 days and hires 60

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

Hide Tags

1 KUDOS received
Manager
Manager
User avatar
G
Joined: 13 Jun 2012
Posts: 181
Location: United States
WE: Supply Chain Management (Computer Hardware)
GMAT ToolKit User
A contractor undertakes to do a job within 20 days and hires 60 [#permalink]

Show Tags

New post 02 Jan 2018, 15:23
1
5
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

68% (02:05) correct 32% (02:53) wrong based on 59 sessions

HideShow timer Statistics

A contractor undertakes to do a job within 20 days and hires 60 people to do it. After 5 days, he realizes that one fifth of the work is done so he hires more people. How many more man he has to hire to complete the job in time?

1. 10
2. 12
3. 15
4. 20
5. 25
Manager
Manager
User avatar
G
Joined: 13 Jun 2012
Posts: 181
Location: United States
WE: Supply Chain Management (Computer Hardware)
GMAT ToolKit User
A contractor undertakes to do a job within 20 days and hires 60 [#permalink]

Show Tags

New post Updated on: 02 Jan 2018, 17:41
What am I doing wrong Can you please help? VeritasPrepKarishma

60 men *20 days= Total number of work 1200
Now after 5 days the amount of work that should be done was 5*60=300 but one fifth of the work was done ie 1200*1/5= 240
which means he still has= 960 amount of work
Let X be the number of men, So (60+x)15=960.. which is 4.

Originally posted by Turkish on 02 Jan 2018, 15:31.
Last edited by Turkish on 02 Jan 2018, 17:41, edited 1 time in total.
1 KUDOS received
Manager
Manager
User avatar
S
Joined: 20 Feb 2017
Posts: 88
Location: United States
Premium Member
Re: A contractor undertakes to do a job within 20 days and hires 60 [#permalink]

Show Tags

New post 02 Jan 2018, 16:36
1
Turkish wrote:
What am I doing wrong

60 men *20 days= Total number of work 1200
Now after 5 days the amount of work that should be done was 5*60=300 but one fifth of the work was done ie 1200*1/5= 240
which means he still has= 960 amount of work
Let X be the number of men, So (60+x)15=960.. which is 4.


You are missing that initial estimation of contractor was wrong.

60 people were able to complete only 1/5 of work in 5 days. So For person, it is 1500 days work not 1200.

Hope it helps.

Sent from my SM-G955F using GMAT Club Forum mobile app
_________________

*****************************************************************
Kudos are always welcome.

VP
VP
avatar
P
Joined: 07 Dec 2014
Posts: 1034
A contractor undertakes to do a job within 20 days and hires 60 [#permalink]

Show Tags

New post 02 Jan 2018, 19:23
Turkish wrote:
A contractor undertakes to do a job within 20 days and hires 60 people to do it. After 5 days, he realizes that one fifth of the work is done so he hires more people. How many more man he has to hire to complete the job in time?

1. 10
2. 12
3. 15
4. 20
5. 25


let 1/x=rate of one man for one day
60*1/x*5 days=1/5 of work
x=1500 days
let y=total men needed to finish job on time
y*1/1500*15 days=4/5 of work
y=80 men
80-60=20 more men needed
D
Expert Post
1 KUDOS received
GMAT Club Legend
GMAT Club Legend
User avatar
P
Joined: 16 Oct 2010
Posts: 8127
Location: Pune, India
Re: A contractor undertakes to do a job within 20 days and hires 60 [#permalink]

Show Tags

New post 02 Jan 2018, 23:02
1
2
Turkish wrote:
What am I doing wrong Can you please help? VeritasPrepKarishma

60 men *20 days= Total number of work 1200
Now after 5 days the amount of work that should be done was 5*60=300 but one fifth of the work was done ie 1200*1/5= 240
which means he still has= 960 amount of work
Let X be the number of men, So (60+x)15=960.. which is 4.


Here is the problem - total amount of work to be done is not 1200.
60 people in 5 days did 60*5 = 300 man days work which is 1/5th of total work. So total work is actually 300*5 = 1500 man days.

So he has to do 1500 - 300 = 1200 man days of work in 15 days.
HE needs 1200/15 = 80 men to do it i.e. 20 more.
_________________

Karishma
Private Tutor for GMAT
Contact: bansal.karishma@gmail.com

Re: A contractor undertakes to do a job within 20 days and hires 60   [#permalink] 02 Jan 2018, 23:02
Display posts from previous: Sort by

A contractor undertakes to do a job within 20 days and hires 60

  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®.