Last visit was: 19 Nov 2025, 15:42 It is currently 19 Nov 2025, 15:42
Home
GMAT
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
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
Back to Forum
Create Topic
User avatar
getzgetzu
User avatar
Joined: 08 Aug 2005
Last visit: 09 Aug 2006
Posts: 215
Own Kudos:
388
 [31]
Posts: 215
Kudos: 388
 [31]
Division R of Company Q has 1,000 employees. What is the average (arit 01 Dec 2005, 00:34
3
Kudos
Add Kudos
27
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

5% (low)

Question Stats:

86% (01:10) correct 14% (01:05) wrong based on 1266 sessions

History

Date
Time
Result
Not Attempted Yet
Division R of Company Q has 1,000 employees. What is the average (arithmetic mean) annual salary of the employees at Company Q?

(1) The average annual salary of the employees in Division R is $30,000.
(2) The average annual salary of the employees at Company Q who are not in Division R is $35,000.
ShowHide Answer
Official Answer
E
Most Helpful Reply
avatar
pmenon
avatar
Joined: 28 Dec 2005
Last visit: 01 Jul 2009
Posts: 692
Own Kudos:
600
 [7]
Given Kudos: 2
Posts: 692
Kudos: 600
 [7]
Division R of Company Q has 1,000 employees. What is the average (arit 02 Apr 2009, 17:32
5
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
Yes, E for me as well. C is the trap answer because it makes you think that since you have the two averages, you know the overall average.

Dont forget though that you need to know the total # of employees to determine overall average, which neither of the statements allow to us to deduce.
General Discussion
User avatar
GMATT73
User avatar
Joined: 29 Jan 2005
Last visit: 28 Dec 2011
Posts: 2,877
Own Kudos:
1,256
 [1]
Posts: 2,877
Kudos: 1,256
 [1]
Division R of Company Q has 1,000 employees. What is the average (arit 01 Dec 2005, 09:15
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
We do not know the total number of employees in the company.

Therefore, (E)
User avatar
domleon
User avatar
Joined: 14 Jun 2007
Last visit: 22 May 2009
Posts: 77
Own Kudos:
87
Location: Vienna, Austria
Posts: 77
Kudos: 87
Division R of Company Q has 1,000 employees. What is the average (arit 15 Oct 2008, 01:48
Kudos
Add Kudos
Bookmarks
Bookmark this Post
cant we just add both averages together and then divide over 2? i know it´s a stupid question but pls guys be so kind and tell me logically why not :-)

thank you
User avatar
scthakur
User avatar
Joined: 17 Jun 2008
Last visit: 30 Jul 2009
Posts: 609
Own Kudos:
449
 [3]
Posts: 609
Kudos: 449
 [3]
Division R of Company Q has 1,000 employees. What is the average (arit 15 Oct 2008, 02:29
3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
domleon
cant we just add both averages together and then divide over 2? i know it´s a stupid question but pls guys be so kind and tell me logically why not :-)

thank you
Show more

No. That cannot be done. Check the following.

if total employees of division A is x1 and total salary is s1 then average = s1/x1.
If rest of employees is x2 and total salary of these is s2 then average = s2/x2.

Sum of the two averages = (s1/x1) + (s2/x2).

However, average at the company level = (s1+s2)/(x1+x2) and this is not the same as (s1/x1) + (s2/x2).

I hope, this helps.
User avatar
walker
User avatar
Joined: 17 Nov 2007
Last visit: 25 May 2025
Posts: 2,398
Own Kudos:
10,717
 [4]
Given Kudos: 362
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Expert
Expert reply
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Posts: 2,398
Kudos: 10,717
 [4]
Division R of Company Q has 1,000 employees. What is the average (arit 24 Mar 2010, 15:25
1
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
We can express the average annual salary of Company Q as:

\(S = \frac{S_r * N_r+ S_{not-r}*N_{not-r}}{N_r+N_{not-r}}\)

where
- \(S_r\) - The average annual salary of the employees in Division R
- \(S_{not-r}\) - The average annual salary of the employees who are not in Division R
- \(N_r\) - The number of employees in Division R
- \(N_{not-r}\) - The number of employees who are not in Division R

So, we don't know the number of employees who are not in Division R.

You can also use huge/tiny numbers to check your answer. If \(N_{not-r}=0\) or only 1 employee, S = 30K or will be very close to 30K. At the same time, if \(N_{not-r}>>1000\), S will be very close to 35K. So we need to know at least \(\frac{N_{not-r}}{N_r}\) ratio.
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,589
Own Kudos:
1,079
Posts: 38,589
Kudos: 1,079
Division R of Company Q has 1,000 employees. What is the average (arit 23 Apr 2024, 22:30
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Moderators:
Bunuel
Math Expert
105390 posts
kingbucky
496 posts