Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

It is currently 25 May 2017, 02:56

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

The average (arithmetic mean) of a, b, c, d, e is 7. What is

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

Hide Tags

Intern
Intern
avatar
Joined: 20 Jun 2011
Posts: 46
Followers: 1

Kudos [?]: 102 [0], given: 1

The average (arithmetic mean) of a, b, c, d, e is 7. What is [#permalink]

Show Tags

New post 28 Jul 2012, 15:28
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

67% (02:33) correct 33% (00:37) wrong based on 96 sessions

HideShow timer Statistics

The average (arithmetic mean) of a, b, c, d, e is 7. What is the average of a, b, c, d, e, f ?

(1) The average of b, c, d, e, f is 9.

(2) The average of b, c, d, e is 11.
[Reveal] Spoiler: OA

Last edited by Bunuel on 29 Jul 2012, 00:34, edited 1 time in total.
Edited the question.
Manager
Manager
User avatar
Affiliations: Project Management Professional (PMP)
Joined: 30 Jun 2011
Posts: 209
Location: New Delhi, India
Followers: 5

Kudos [?]: 74 [0], given: 12

Re: The average (arithmetic mean) of a,b,c,d,e is 7. What is the [#permalink]

Show Tags

New post 28 Jul 2012, 20:58
superpus07 wrote:
The average (arithmetic mean) of a,b,c,d,e is 7. What is the average of a,b,c,d,e,f ?

(1) The average of b,c,d,e,f is 9.

(2) The average of b,c,d,e is 11.

Hi

Q says (a+b+c+d+e)/5=7
=>a+b+c+d+e=35----1)

From startement 1:
(b+c+d+e+f)/5=9;
=> b+c+d+e+f=45---- 2)

from 1) and 2) we can't solve for F hence INSUFFICIENT

from statement 2
(b+c+d+e)/4=11
b+c+d+e=44--3)
from 1) and 3) we can't solve for F hence INSUFFICIENT

combining 1 & 2 statements
from 2) and 3) 23 can easily solve for F

Hence answer is C
_________________

Best
Vaibhav

If you found my contribution helpful, please click the +1 Kudos button on the left, Thanks

Expert Post
Math Expert
User avatar
P
Joined: 02 Sep 2009
Posts: 38862
Followers: 7728

Kudos [?]: 106080 [0], given: 11607

Re: The average (arithmetic mean) of a, b, c, d, e is 7. What is [#permalink]

Show Tags

New post 29 Jul 2012, 00:43
Expert's post
1
This post was
BOOKMARKED
The average (arithmetic mean) of a, b, c, d, e is 7. What is the average of a, b, c, d, e, f ?

It's almost always better to express the average in terms of the sum.
Given: \(a+b+c+d+e=5*7\).
Question: \(a+b+c+d+e+f=?\) --> \(5*7+f=?\) So basically we are asked to find the value of \(f\).

(1) The average of b, c, d, e, f is 9 --> \(b+c+d+e+f=5*9\). Not sufficient.

(2) The average of b, c, d, e is 11 --> \(b+c+d+e=4*11\). Not sufficient.

(1)+(2) Subtract (2) from (1): \(f=5*9-4*11=1\). Sufficient.

Answer: C.
_________________

New to the Math Forum?
Please read this: 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

BSchool Forum Moderator
User avatar
G
Joined: 12 Aug 2015
Posts: 2135
Followers: 73

Kudos [?]: 608 [0], given: 553

GMAT ToolKit User CAT Tests
Re: The average (arithmetic mean) of a, b, c, d, e is 7. What is [#permalink]

Show Tags

New post 21 Dec 2016, 20:27
Nice one.
Here is what i did in this one =>
Mean =35+f/6
We need the value of f

Statement 1=>
b+c+d+e+f=45
No clue of a => no clue of f=>not sufficient

Hence not sufficient

Statement 2-->
No clue of f => Not sufficient

Combing them => f=1
Hence mean = 35+1/6 = 6
Hence sufficient
Hence C

_________________

Give me a hell yeah ...!!!!!

Re: The average (arithmetic mean) of a, b, c, d, e is 7. What is   [#permalink] 21 Dec 2016, 20:27
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic If the average (arithmetic mean) of a, b, and c is (a+2b)/3, what is t MathRevolution 2 11 May 2017, 01:20
Experts publish their posts in the topic If the average (arithmetic mean) of 3 integers a, b, and c is 5, what MathRevolution 4 19 Dec 2016, 20:07
5 Experts publish their posts in the topic If m is the arithmetic mean (average) of 4 integers a, b, c, and d and Bunuel 3 25 Apr 2017, 08:12
2 What is the average (arithmetic mean) of a, b, and c ? AbdurRakib 3 21 Dec 2016, 16:41
5 Experts publish their posts in the topic What is the average (arithmetic mean) of A, B, and 4C? prateekbhatt 4 21 Dec 2016, 18:08
Display posts from previous: Sort by

The average (arithmetic mean) of a, b, c, d, e is 7. What is

  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 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®.