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

It is currently 21 Jun 2018, 18:40

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

Of the 1400 college teachers surveyed, 42% said they consid

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

Hide Tags

Expert Post
1 KUDOS received
Veritas Prep GMAT Instructor
User avatar
P
Joined: 16 Oct 2010
Posts: 8102
Location: Pune, India
Re: Of the 1400 college teachers surveyed, 42% said they consid [#permalink]

Show Tags

New post 28 Apr 2017, 06:08
1
vijaisingh2001 wrote:
(2)
M + W = 1400

who wants to research = 1400* .42 = (M+W)* .42 = 588
since 1400= M+W so we can replace M+W with 1400

now men who want to do research= 288 = .42M
so .42(M+W )= 588
.42M +.42 W= 588
288 +.42 W = 588
so we can calculate W

so why this is wrong?



now men who want to do research= 288 = .42M

How do you get this? 42% of total teachers said that engaging in research is essential. We don't know what percent of men thought so. It is possible that only 30% men considered research essential while 55% women considered research essential. Both together could lead to a number of 42% depending on the ratio of number of men and women. This is just one example. The figure of 42% could be obtained in many different ways.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199

Veritas Prep Reviews

Intern
Intern
avatar
S
Joined: 20 Mar 2016
Posts: 34
GMAT 1: 530 Q33 V28
GMAT ToolKit User Premium Member
Of the 1400 college teachers surveyed, 42% said they consid [#permalink]

Show Tags

New post 06 Jun 2017, 18:48
Bunuel wrote:
Of the 1400 college teachers surveyed, 42% said they considered engaging in research an essential goal. How many of the college teacher surveyed were women?

(1) In the survey 36% of men and 50% of women said that they consider engaging in research activity an essential goal:

\(m+w=1400\) and \(1400*0.42=0.36*m+0.5*w\). Two unknowns two distinct linear equations. Sufficient.

(2) In the survey 288 men said that they consider engaging in research activity an essential goal"

From this we can calculate only that \(1400*0.42-288=300\) women consider engaging in research activity an essential goal. No other info. Not sufficient.

Answer: A.


Absolutely a brilliant explanation! I had always used the matrix box approach but not anymore '

Thank you Bunuel sir,
Jat
_________________

Jat

Manager
Manager
avatar
G
Joined: 21 Jul 2015
Posts: 166
Reviews Badge CAT Tests
Of the 1400 college teachers surveyed, 42% said they consid [#permalink]

Show Tags

New post 23 Jan 2018, 19:57
Bunuel, VeritasPrepKarishma

I understand this is a weighted averages problem. But I am having a hard time understanding how we take percentages as the "average" for a group. To me 'averages' are an absolute number (not %). Could you please explain what am I missing here?

BTW, Can you also check if my weighted average solution for this problem is correct?

If we apply the weighted average concept here for choice A:

AvgM = 36%, AvgW = 50%. Total Average (AvgT) = 42%. So since we know all three averages, we can calculate the ratio of the weights using the formula:

Wm/Ww = AvgW - AvgT/AvgT - AvgM. This will give us the ratio of M/W and since we have total of all surveyed, we can find number of women.

I think I am confused as to why we are taking these percentages as Average for that group.
_________________

Please take a moment to hit Kudos if my post helps.

Expert Post
1 KUDOS received
Veritas Prep GMAT Instructor
User avatar
P
Joined: 16 Oct 2010
Posts: 8102
Location: Pune, India
Re: Of the 1400 college teachers surveyed, 42% said they consid [#permalink]

Show Tags

New post 23 Jan 2018, 21:42
1
sdlife wrote:
Bunuel, VeritasPrepKarishma

I understand this is a weighted averages problem. But I am having a hard time understanding how we take percentages as the "average" for a group. To me 'averages' are an absolute number (not %). Could you please explain what am I missing here?

BTW, Can you also check if my weighted average solution for this problem is correct?

If we apply the weighted average concept here for choice A:

AvgM = 36%, AvgW = 50%. Total Average (AvgT) = 42%. So since we know all three averages, we can calculate the ratio of the weights using the formula:

Wm/Ww = AvgW - AvgT/AvgT - AvgM. This will give us the ratio of M/W and since we have total of all surveyed, we can find number of women.

I think I am confused as to why we are taking these percentages as Average for that group.


Yes, it is and your method is correct.

Percentages are just a way of expressing concentration.
So you have two groups made of two ingredients - "people who consider engaging in research essential" and "people who don't consider it essential"

So we work with the percentage of "people who consider engaging in research essential". It is the same as working with the concentration of one of the ingredients.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199

Veritas Prep Reviews

Re: Of the 1400 college teachers surveyed, 42% said they consid   [#permalink] 23 Jan 2018, 21:42

Go to page   Previous    1   2   [ 24 posts ] 

Display posts from previous: Sort by

Of the 1400 college teachers surveyed, 42% said they consid

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


cron

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