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

It is currently 15 Oct 2019, 17:03

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

If a racehorse runs an average(arithmetic mean) of m miles per race fo

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

Hide Tags

Find Similar Topics 
Manager
Manager
avatar
B
Joined: 13 Sep 2016
Posts: 115
GMAT 1: 800 Q51 V51
If a racehorse runs an average(arithmetic mean) of m miles per race fo  [#permalink]

Show Tags

New post 18 Oct 2016, 22:24
2
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

82% (01:09) correct 18% (01:44) wrong based on 64 sessions

HideShow timer Statistics

If a racehorse runs an average(arithmetic mean) of m miles per race for r races and then runs n miles in its next race, what is the average number of miles the horse has run for the r + 1 races?

a) (rm + n)/r+1
b) (m + n)/r+1
c) (m + n)/r
d) r(m + n)/r+1
e) (m + rn)/r+1

Please assist with above problem.
Manager
Manager
avatar
Joined: 29 Aug 2008
Posts: 106
Re: If a racehorse runs an average(arithmetic mean) of m miles per race fo  [#permalink]

Show Tags

New post 18 Oct 2016, 23:17
1
Average miles ran per race = m for r no of races. So total miles = m*r

Miles ran in next race = n

Total Miles ran = m*r + n in r+1 races

Average miles = Total miles/Total no of races = (m*r + n)/(r + 1)

Option A

HTH
Board of Directors
User avatar
D
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4778
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User
Re: If a racehorse runs an average(arithmetic mean) of m miles per race fo  [#permalink]

Show Tags

New post 19 Oct 2016, 08:24
1
alanforde800Maximus wrote:
If a racehorse runs an average(arithmetic mean) of m miles per race for r races and then runs n miles in its next race, what is the average number of miles the horse has run for the r + 1 races?

a) (rm + n)/r+1
b) (m + n)/r+1
c) (m + n)/r
d) r(m + n)/r+1
e) (m + rn)/r+1

Please assist with above problem.


Total distance run in \(r\) races = \(rm\)
Distance run in last race is \(n\)

So, Total Distance Run = \(rm\) \(+\) \(n\)
Total run = \(r + 1\)

Hence average will be \(\frac{rm + n}{r+1}\)

So, Correct answer will be (A)

_________________
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 )
Target Test Prep Representative
User avatar
D
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8048
Location: United States (CA)
Re: If a racehorse runs an average(arithmetic mean) of m miles per race fo  [#permalink]

Show Tags

New post 05 Dec 2017, 18:52
1
alanforde800Maximus wrote:
If a racehorse runs an average(arithmetic mean) of m miles per race for r races and then runs n miles in its next race, what is the average number of miles the horse has run for the r + 1 races?

a) (rm + n)/r+1
b) (m + n)/r+1
c) (m + n)/r
d) r(m + n)/r+1
e) (m + rn)/r+1


We are given that a racehorse runs an average (arithmetic mean) of m miles per race for r races and then runs n miles in its next race. We need to determine the average number of miles the horse has run for r + 1 races. Let’s plug the given information into the average formula.

average = sum/quantity

Since the racehorse runs an average (arithmetic mean) of m miles per race for r races, the initial sum = mr and the initial quantity is r.

Since the racehorse then runs n miles in its next race, the new sum is mr + n and the new quantity is r + 1.

Thus, the average number of miles that the horse runs for r + 1 races is:

(mr + n)/(r + 1)

Answer: A
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 15254
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: If a racehorse runs an average(arithmetic mean) of m miles per race fo  [#permalink]

Show Tags

New post 24 Jan 2018, 21:02
Hi All,

This question can be solved Algebraically or by TESTing VALUES. Here's how you can use the second method:

IF...
M = 2
R = 3
Then the racecourse ran (2 miles/race)(3 races) = 6 miles

N = 4
So the horse ran 4 miles in that 1 race.

Thus, the average for the 4 races was (10 miles)/(4 races) = 2.5 miles/race

There's only one answer that matches...

Final Answer:

GMAT assassins aren't born, they're made,
Rich
_________________
Contact Rich at: Rich.C@empowergmat.com
Image


The Course Used By GMAT Club Moderators To Earn 750+

souvik101990 Score: 760 Q50 V42 ★★★★★
ENGRTOMBA2018 Score: 750 Q49 V44 ★★★★★
Board of Directors
User avatar
D
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4778
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User
Re: If a racehorse runs an average(arithmetic mean) of m miles per race fo  [#permalink]

Show Tags

New post 25 Jan 2018, 08:30
alanforde800Maximus wrote:
If a racehorse runs an average(arithmetic mean) of m miles per race for r races and then runs n miles in its next race, what is the average number of miles the horse has run for the r + 1 races?

a) (rm + n)/r+1
b) (m + n)/r+1
c) (m + n)/r
d) r(m + n)/r+1
e) (m + rn)/r+1

Please assist with above problem.


Total distance run in r races is \(mr\)
Total distance run after n miles is \(mr + n\)

So, Average Distance run is \(\frac{mr + n}{r + 1}\) , Answer must be (A)
_________________
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 )
GMAT Club Bot
Re: If a racehorse runs an average(arithmetic mean) of m miles per race fo   [#permalink] 25 Jan 2018, 08:30
Display posts from previous: Sort by

If a racehorse runs an average(arithmetic mean) of m miles per race fo

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





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne