Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 28 Apr 2016, 17:35

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# m02#7

Author Message
Manager
Joined: 18 Aug 2010
Posts: 90
Followers: 1

Kudos [?]: 6 [0], given: 22

### Show Tags

04 Feb 2011, 03:40
Andy, George and Sally are a team of consultants working on Project Alpha. They have an eight hour deadline to complete the project. The team members work at constant rates throughout the eight hour period. If the team of three has to begin work now and no one else can work on this project, will Project Alpha be completed by the deadline?

1. Sally can finish the project alone in $$4k+7$$ hours, where $$k$$ is a positive integer with a minimum value of 1 and a maximum value of 5.
2. Working alone, George will take $$2k+1$$ hours and Andy will take $$3+2k$$ hours, where $$k$$ is a positive integer with a minimum value of 1 and a maximum value of 5

(C) 2008 GMAT Club - m02#7

* Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient
* Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient
* BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient
* EACH statement ALONE is sufficient
* Statements (1) and (2) TOGETHER are NOT sufficient

i ve a question here.: i got that both George and Andy can complete a Job in 143/24 hour
that is approx . 5.95h not enough to reach 8 h. deadline .

so can anybody advice where my logic went wrong?
thanks
Director
Status: -=Given to Fly=-
Joined: 04 Jan 2011
Posts: 834
Location: India
Schools: Haas '18, Kelley '18
GMAT 1: 650 Q44 V37
GMAT 2: 710 Q48 V40
GMAT 3: 750 Q51 V40
GPA: 3.5
WE: Education (Education)
Followers: 47

Kudos [?]: 182 [1] , given: 78

### Show Tags

04 Feb 2011, 06:08
1
KUDOS
Well, this is how I would solve the problem:

Statement 1:

Sally takes 4k+7 hrs to complete the thing alone.
So time taken by Sally = 11, 15, 19, 23 or 27 hrs.

We know nothing about how fast George and Andy work!

Thus - NOT SUFFICIENT!

Statement 2:
George - 2k+1 hr
Time - 3, 5, 7, 9 or 11

Andy - 3+2k
Time - 5, 7, 9, 11 or 13

Assume the worst case scenario - Only George and Andy are working and they're both taking their own sweet time:

Therefore, time : 13x11/(13+11) = 13x11/24 = 143/24

Quick Math:
24x8 = 192

Thus, 143/24 is less than 8 :D

Which means:
George and Andy can finish the job before the 8hr deadline if they work together (irrespective of how fast or slow they work and independent of Sally's work rate!)

Ans: B
_________________

"Wherever you go, go with all your heart" - Confucius

1. How to Review and Analyze your Mistakes (Post by BB at GMAT Club)

2. 4 Steps to Get the Most out out of your CATs (Manhattan GMAT Blog)

My Experience With GMAT

1. From 650 to 710 to 750 - My Tryst With GMAT

2. Quest to do my Best - My GMAT Journey Log

Director
Status: -=Given to Fly=-
Joined: 04 Jan 2011
Posts: 834
Location: India
Schools: Haas '18, Kelley '18
GMAT 1: 650 Q44 V37
GMAT 2: 710 Q48 V40
GMAT 3: 750 Q51 V40
GPA: 3.5
WE: Education (Education)
Followers: 47

Kudos [?]: 182 [1] , given: 78

### Show Tags

04 Feb 2011, 06:09
1
KUDOS
One more thing:

This is not a value Question. It is a 'Yes/No' question. So you don't have to calculate the exact value
_________________

"Wherever you go, go with all your heart" - Confucius

1. How to Review and Analyze your Mistakes (Post by BB at GMAT Club)

2. 4 Steps to Get the Most out out of your CATs (Manhattan GMAT Blog)

My Experience With GMAT

1. From 650 to 710 to 750 - My Tryst With GMAT

2. Quest to do my Best - My GMAT Journey Log

Manager
Joined: 18 Aug 2010
Posts: 90
Followers: 1

Kudos [?]: 6 [1] , given: 22

### Show Tags

04 Feb 2011, 06:12
1
KUDOS
AmrithS wrote:
Well, this is how I would solve the problem:

Statement 1:

Sally takes 4k+7 hrs to complete the thing alone.
So time taken by Sally = 11, 15, 19, 23 or 27 hrs.

We know nothing about how fast George and Andy work!

Thus - NOT SUFFICIENT!

Statement 2:
George - 2k+1 hr
Time - 3, 5, 7, 9 or 11

Andy - 3+2k
Time - 5, 7, 9, 11 or 13

Assume the worst case scenario - Only George and Andy are working and they're both taking their own sweet time:

Therefore, time : 13x11/(13+11) = 13x11/24 = 143/24

Quick Math:
24x8 = 192

Thus, 143/24 is less than 8 :D

Which means:
George and Andy can finish the job before the 8hr deadline if they work together (irrespective of how fast or slow they work and independent of Sally's work rate!)

Ans: B

OMG !!! very very silly mistake. thanks for opening my eyes
+kudo
Re: m02#7   [#permalink] 04 Feb 2011, 06:12
Display posts from previous: Sort by

# m02#7

Moderator: Bunuel

 Powered by phpBB © phpBB Group and phpBB SEO 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®.