It is currently 22 Feb 2018, 10:50

TODAY:

MIT Sloan Releasing 1st Wave of Interview Invites - Join GMATClub CHAT for Live Updates


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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

At a recent company meeting, there were 14 project managers and 10 eng

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

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43867
At a recent company meeting, there were 14 project managers and 10 eng [#permalink]

Show Tags

New post 21 Mar 2017, 04:02
Expert's post
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

93% (01:36) correct 7% (01:54) wrong based on 62 sessions

HideShow timer Statistics

At a recent company meeting, there were 14 project managers and 10 engineers in attendance, with an overall average age of 31. If the average age of the project managers was 36, what was the average age of the engineers?

A. 24
B. 25
C. 26
D. 28
E. 30
[Reveal] Spoiler: OA

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Expert Post
Top Contributor
SVP
SVP
User avatar
P
Joined: 11 Sep 2015
Posts: 2058
Location: Canada
Re: At a recent company meeting, there were 14 project managers and 10 eng [#permalink]

Show Tags

New post 21 Mar 2017, 07:46
Expert's post
Top Contributor
1
This post was
BOOKMARKED
Bunuel wrote:
At a recent company meeting, there were 14 project managers and 10 engineers in attendance, with an overall average age of 31. If the average age of the project managers was 36, what was the average age of the engineers?

A. 24
B. 25
C. 26
D. 28
E. 30


This is a nice weighted averages question.

Weighted average of groups combined = (group A proportion)(group A average) + (group B proportion)(group B average) + (group C proportion)(group C average) + ...

So: average age of COMBINED workers = (proportion of project managers)(average age of project managers) + (proportion of engineers)(average age of engineers)

We have a total of 24 workers (14 project managers + 10 engineers = 24 workers)
So, the proportion of project managers = 14/24 = 7/12
The proportion of engineers = 10/24 = 5/12
Let E = average age of engineers

Now, plug everything into the formula to get:
31 = (7/12)(36) + (5/12)(E)
Simplify: 31 = 21 + 5E/12
Subtract 21 from both sides: 10 = 5E/12
Multiply both sides by 12 to get: 120 = 5E
Solve: E = 24

Answer:
[Reveal] Spoiler:
A


RELATED VIDEO

_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Expert Post
e-GMAT Representative
User avatar
S
Joined: 04 Jan 2015
Posts: 806
Re: At a recent company meeting, there were 14 project managers and 10 eng [#permalink]

Show Tags

New post 21 Mar 2017, 07:46
Bunuel wrote:
At a recent company meeting, there were 14 project managers and 10 engineers in attendance, with an overall average age of 31. If the average age of the project managers was 36, what was the average age of the engineers?

A. 24
B. 25
C. 26
D. 28
E. 30


Hey,

PFB the solution. :)

    • Number of Project Managers = 14
    • Average Age of Project Managers = 36
    • Number of Engineers = 10
    • Average Age of Engineers = X (assume)
    • Overall Average = 31

Thus, we can write

Overall Average = [(Number of Project Managers *Average Age of Project Managers + Number of Engineers*Average Age of Engineers)/[Number of Project Managers+Number of Engineers]

\(31 = \frac{(14*36 + 10X)}{(14+10)}\)

\(10X = 24 * 31 - 14 *36 = 24*31 - 24 * 21\)

\(10 X = 10 * 24\)

\(X = 24\)

Thus, the correct answer is Option A


Thanks,
Saquib
Quant Expert
e-GMAT

Register for our Free Session on Number Properties (held every 3rd week) to solve exciting 700+ Level Questions in a classroom environment under the real-time guidance of our Experts :)

Image
_________________












| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

Board of Directors
User avatar
G
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 3326
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User Premium Member
Re: At a recent company meeting, there were 14 project managers and 10 eng [#permalink]

Show Tags

New post 21 Mar 2017, 10:28
Bunuel wrote:
At a recent company meeting, there were 14 project managers and 10 engineers in attendance, with an overall average age of 31. If the average age of the project managers was 36, what was the average age of the engineers?

A. 24
B. 25
C. 26
D. 28
E. 30


\(24*31 = 14*36 + 10*e\)

\(Or, 12*31 = 7*36 +5e\)

\(Or, 372 = 252 + 5e\)

\(Or, 120 = 5e\)

\(Or, e = 24\)

Thus, the average age of the engineers is (A) 24 years...
_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Board of Directors
User avatar
G
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 3326
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User Premium Member
Re: At a recent company meeting, there were 14 project managers and 10 eng [#permalink]

Show Tags

New post 21 Mar 2017, 10:28
Bunuel wrote:
At a recent company meeting, there were 14 project managers and 10 engineers in attendance, with an overall average age of 31. If the average age of the project managers was 36, what was the average age of the engineers?

A. 24
B. 25
C. 26
D. 28
E. 30


\(24*31 = 14*36 + 10*e\)

\(Or, 12*31 = 7*36 +5e\)

\(Or, 372 = 252 + 5e\)

\(Or, 120 = 5e\)

\(Or, e = 24\)

Thus, the average age of the engineers is (A) 24 years...
_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Re: At a recent company meeting, there were 14 project managers and 10 eng   [#permalink] 21 Mar 2017, 10:28
Display posts from previous: Sort by

At a recent company meeting, there were 14 project managers and 10 eng

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


GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.