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

It is currently 19 Nov 2018, 01:26

INSEAD R1 Results This Week!

First Decision Reported on Decision Tracker  |  Join INSEAD Chat to Calm Your Nerves & Catch the Latest Action


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 in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
  • How to QUICKLY Solve GMAT Questions - GMAT Club Chat

     November 20, 2018

     November 20, 2018

     09:00 AM PST

     10:00 AM PST

    The reward for signing up with the registration form and attending the chat is: 6 free examPAL quizzes to practice your new skills after the chat.
  • The winning strategy for 700+ on the GMAT

     November 20, 2018

     November 20, 2018

     06:00 PM EST

     07:00 PM EST

    What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL.

A researcher has determined that she requires a minimum of n

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

Hide Tags

Intern
Intern
avatar
Joined: 26 Jun 2012
Posts: 24
Location: Germany
Concentration: Leadership, Finance
GMAT 1: 570 Q31 V39
GMAT 2: 710 Q43 V44
GMAT ToolKit User
A researcher has determined that she requires a minimum of n  [#permalink]

Show Tags

New post 22 Jul 2013, 03:55
2
13
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

57% (01:25) correct 43% (01:33) wrong based on 437 sessions

HideShow timer Statistics

A researcher has determined that she requires a minimum of n responses to a survey for the results to be valid. If p% of the surveyed individuals fail to respond to the survey, how many individuals, in terms of n and p, must the researcher survey to produce twice the minimum required number of responses?

A.\(\frac{{200n}}{{100-p}}\)

B.\(\frac{{2n}}{{100-p}}\)

C.\(\frac{{200n}}{{p}}\)

D.\(\frac{{2n(100+p)}}{{100}}\)

E.\(\frac{{2n+2np}}{{100}}\)


I took some time to solve it algebraically. Have fun!
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50658
Re: A researcher has determined that she requires a minimum of n  [#permalink]

Show Tags

New post 22 Jul 2013, 04:10
1
1
kingflo wrote:
A researcher has determined that she requires a minimum of n responses to a survey for the results to be valid. If p% of the surveyed individuals fail to respond to the survey, how many individuals, in terms of n and p, must the researcher survey to produce twice the minimum required number of responses?

A.\(\frac{{200n}}{{100-p}}\)

B.\(\frac{{2n}}{{100-p}}\)

C.\(\frac{{200n}}{{p}}\)

D.\(\frac{{2n(100+p)}}{{100}}\)

E.\(\frac{{2n+2np}}{{100}}\)


I took some time to solve it algebraically. Have fun!


Say x individuals must be surveyed.

p% of the surveyed individuals fail to respond --> the number of individuals who did NOT fail to respond = \(x-x*\frac{p}{100}\).
The above must be equal to 2n, so:

\(x-x*\frac{p}{100}=2n\) --> \(x(1-\frac{p}{100})=2n\) --> \(x=\frac{200n}{100-p}\).

Answer: A.

Of course one can also use plug-in method to solve this problem.
_________________

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

Manager
Manager
User avatar
B
Joined: 15 Jan 2011
Posts: 101
Re: A researcher has determined that she requires a minimum of n  [#permalink]

Show Tags

New post 28 Jul 2013, 01:23
X - #of surveyed people

(1-P)*X>=2n --> x>=2n/(1-P)

A
Board of Directors
User avatar
P
Joined: 17 Jul 2014
Posts: 2645
Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE: General Management (Transportation)
GMAT ToolKit User Premium Member Reviews Badge
Re: A researcher has determined that she requires a minimum of n  [#permalink]

Show Tags

New post 03 Jan 2016, 12:01
1
suppose x is the number of people she needs to interview
out of the x, only x(100-p/100) answered.
this all is equal to n.
so n = x(100-p/100)
or x= 100n/100-p
since we need twice the number, multiply everything by 2, and get 200n/100-p.
A
Manager
Manager
User avatar
S
Status: Just redeemed Kudos for GMAT Club Test !!
Joined: 14 Sep 2013
Posts: 94
Location: Bangladesh
GMAT 1: 530 Q40 V23
GPA: 3.56
WE: Analyst (Commercial Banking)
GMAT ToolKit User Premium Member
Re: A researcher has determined that she requires a minimum of n  [#permalink]

Show Tags

New post 22 Jan 2016, 17:27
1
Unitary method seems more comprehensible to me.

Given that p% of the surveyed individuals fail to respond.

So individual who NOT failed to respond = (100-P)%

That means,

To get (100-P) responses, 100 individual is surveyed.
For 1 response, 100 / (100-P) individual is surveyed.
For 2n responses, (100*2n) / (100-P) individual is surveyed.

Answer: (A) 200n / (100-P)
_________________

______________
KUDOS please, if you like the post or if it helps :-)
"Giving kudos" is a decent way to say "Thanks"

Master with structure - Numerical comparison [source: economist.com] https://gmatclub.com/forum/master-with-structure-numerical-comparison-233657.html#p1801987

Senior Manager
Senior Manager
User avatar
G
Joined: 03 Apr 2013
Posts: 278
Location: India
Concentration: Marketing, Finance
GMAT 1: 740 Q50 V41
GPA: 3
GMAT ToolKit User
Re: A researcher has determined that she requires a minimum of n  [#permalink]

Show Tags

New post 09 Jul 2016, 20:01
Bunuel wrote:
kingflo wrote:
A researcher has determined that she requires a minimum of n responses to a survey for the results to be valid. If p% of the surveyed individuals fail to respond to the survey, how many individuals, in terms of n and p, must the researcher survey to produce twice the minimum required number of responses?

A.\(\frac{{200n}}{{100-p}}\)

B.\(\frac{{2n}}{{100-p}}\)

C.\(\frac{{200n}}{{p}}\)

D.\(\frac{{2n(100+p)}}{{100}}\)

E.\(\frac{{2n+2np}}{{100}}\)


I took some time to solve it algebraically. Have fun!


Say x individuals must be surveyed.

p% of the surveyed individuals fail to respond --> the number of individuals who did NOT fail to respond = \(x-x*\frac{p}{100}\).
The above must be equal to 2n, so:

\(x-x*\frac{p}{100}=2n\) --> \(x(1-\frac{p}{100})=2n\) --> \(x=\frac{200n}{100-p}\).

Answer: A.

Of course one can also use plug-in method to solve this problem.

The question is not hard..I got stuck because I found the wording very awkward..is the wording good enough? I'm not feeling right about this one..
_________________

Spread some love..Like = +1 Kudos :)

Senior Manager
Senior Manager
avatar
P
Joined: 26 Jun 2017
Posts: 369
Location: Russian Federation
Concentration: General Management, Strategy
WE: Information Technology (Other)
Re: A researcher has determined that she requires a minimum of n  [#permalink]

Show Tags

New post 08 Sep 2017, 11:58
A question is a little similar to https://gmatclub.com/forum/the-price-of ... 31794.html.
(the opposite similar))
Senior Manager
Senior Manager
User avatar
S
Status: love the club...
Joined: 24 Mar 2015
Posts: 267
Re: A researcher has determined that she requires a minimum of n  [#permalink]

Show Tags

New post 09 Sep 2017, 13:54
Bunuel wrote:
kingflo wrote:
A researcher has determined that she requires a minimum of n responses to a survey for the results to be valid. If p% of the surveyed individuals fail to respond to the survey, how many individuals, in terms of n and p, must the researcher survey to produce twice the minimum required number of responses?

A.\(\frac{{200n}}{{100-p}}\)

B.\(\frac{{2n}}{{100-p}}\)

C.\(\frac{{200n}}{{p}}\)

D.\(\frac{{2n(100+p)}}{{100}}\)

E.\(\frac{{2n+2np}}{{100}}\)


I took some time to solve it algebraically. Have fun!


Say x individuals must be surveyed.

p% of the surveyed individuals fail to respond --> the number of individuals who did NOT fail to respond = \(x-x*\frac{p}{100}\).
The above must be equal to 2n, so:

\(x-x*\frac{p}{100}=2n\) --> \(x(1-\frac{p}{100})=2n\) --> \(x=\frac{200n}{100-p}\).

Answer: A.

Of course one can also use plug-in method to solve this problem.


hi

how can you equate x( 1 - p/100) with 2n ..?

say, p = 10, n = 7....
now 90 people can respond, and 2n = 14

So, 14 = 90 , how come ...?

if the question used the terms "at least", it would be somewhat clear ...

thanks in advance ..
Manager
Manager
avatar
B
Joined: 03 May 2014
Posts: 161
Location: India
WE: Sales (Mutual Funds and Brokerage)
A researcher has determined that she requires a minimum of n  [#permalink]

Show Tags

New post 09 Sep 2017, 19:52
Plugin nos.
Let people surveyed be 100
10% of 100 surveyed do not respond=10
90 surveyed responded=the required no response for the survey to be valid.
Double is 180.
To get 180 you need 200 responders.
Plugin in n=90 and p=10 in the given expression.
1) Start from C

\(\frac{200n}{p}\)

\(\frac{200*90}{10}\)=1800=wrong.

2) Pick A (I checked all the answer choice but for sake of time and effort showing only 2 workings)

\(\frac{200*n}{100-p}\)

\(\frac{200*90}{100-10}\)=200=correct.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 8819
Premium Member
Re: A researcher has determined that she requires a minimum of n  [#permalink]

Show Tags

New post 30 Oct 2018, 02:07
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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

GMAT Club Bot
Re: A researcher has determined that she requires a minimum of n &nbs [#permalink] 30 Oct 2018, 02:07
Display posts from previous: Sort by

A researcher has determined that she requires a minimum of n

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


Copyright

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®.