December 15, 2018 December 15, 2018 10:00 PM PST 11:00 PM PST Get the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299) December 16, 2018 December 16, 2018 07:00 AM PST 09:00 AM PST Get personalized insights on how to achieve your Target Quant Score.
Author 
Message 
TAGS:

Hide Tags

Intern
Joined: 13 Sep 2003
Posts: 42
Location: US

In a nationwide poll, N people were interviewed. If 1/4 of
[#permalink]
Show Tags
02 Nov 2003, 13:41
Question Stats:
73% (02:02) correct 27% (02:36) wrong based on 1252 sessions
HideShow timer Statistics
In a nationwide poll, N people were interviewed. If 1/4 of them answered "yes" to question 1, and of those, 1/3 answered "yes" to question 2, which of the following expressions represents the number of people interviewed who did NOT answer "yes" to both questions? A. N/7 B. 6N/7 C. 5N/12 D. 7N/12 E. 11N/12
Official Answer and Stats are available only to registered users. Register/ Login.




Math Expert
Joined: 02 Sep 2009
Posts: 51218

Re: Survey yes/no
[#permalink]
Show Tags
06 Oct 2010, 03:27
nonameee wrote: In a nationwide poll, N people were interviewed. If 1/4 of them answered "yes" to question 1, and of those, 1/3 answered "yes" to question 2, which of the following expressions represents the number of people interviewed who did NOT answer "yes" to both questions?
A N/7 B 6N/7 C 5N/12 D 7N/12 E 11N/12
Bunuel, can you please look at this question. I personally got E for the answer. But after giving it some thought, I started to doubt it. My reasoning goes like this:
Total: 36
Yes to 1: 9 Yes to 1 and Yes to 2: 1/3 * 9 = 3
No to 1: 369 = 27 No to 1 No to 2: ? No to 1 Yes to 2: ?
So, I don't know how we can calculate No 1 No to 2. I guess that's what the question asks.
Thank you. No, the question asks for {No,No}, {No,Yes}, {Yes,No} any combination but {Yes,Yes}: "the number of people interviewed who did NOT answer "yes" to both questions". If we use your example then: 1/4th of 36 or 9 people answered YES to question 1. Of those, 1/3 answered "yes" to question 2, so 1/3rd of 9 or 3 people answered YES to BOTH question 1 and 2. So YES to both questions answered 3/36=1/12 of N people interviewed and 11/12=11/12 of N people interviewed did NOT answer "yes" to both questions. Hope it's clear.
_________________
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? Extrahard Quant Tests with Brilliant Analytics




Intern
Joined: 27 Aug 2009
Posts: 41
Schools: London Business School

Re: Survey yes/no
[#permalink]
Show Tags
20 Sep 2009, 08:13
Answer E Those who answered yes to both questions = 1/4 x 1/3 = 1/12 So, answer = 1  1/12 = 11/12
_________________
Salaries are low in recession. So, working for kudos now.




Director
Joined: 25 Oct 2008
Posts: 511
Location: Kolkata,India

Re: Survey yes/no
[#permalink]
Show Tags
13 May 2009, 03:44
Q1 {N}  YES {N/4} NO {3N/4}   yes Q2 no Q2 yesQ2 noQ2 {N/12} {N/6} ??? I always approach these kinds of sums with flowcharts(for eg. #124).Here what we need is denoted by a question mark.i.e. NO on both questions.I don't understand this,we have no idea of how 3N/4 is broken up.Help??
_________________
http://gmatclub.com/forum/countdownbeginshasended8548340.html#p649902



Senior Manager
Joined: 27 Jun 2008
Posts: 489
WE 1: Investment Banking  6yrs

Re: Survey yes/no
[#permalink]
Show Tags
13 May 2009, 05:36
You dug this up from the lost pages.
Anyway, E
Q1 Yes No 1/4N 3/4N (11/4) Q2 1/4*1/3N 11/4*1/3N
i.e No to both the questions = 11N/12



Manager
Joined: 10 Jul 2009
Posts: 107
Location: Ukraine, Kyiv

Re: Survey yes/no
[#permalink]
Show Tags
20 Sep 2009, 02:12
sudzpwc wrote: In a nationwide poll, N people were interviewed. If 1/4 of them answered "yes" to question 1, and of those, 1/3 answered "yes" to question 2, which of the following expressions represents the number of people interviewed who did NOT answer "yes" to both questions?
A N/7
B 6N/7
C 5N/12
D 7N/12
E 11N/12 Can anyone, please, explain, why result is E? And post OA. I am getting completely different result: 2/3N. If there are 1/4N people answered yes to q1 and 1/3 of those answered yes to q2. Thus, people who answered yes to q2 is 1/12. and total no of people ans yes is 1/12+1/4=1/3N. So, those who answered NO: N1/3N=2/3N. What do I do wrong? help appreciated.
_________________
Never, never, never give up



Intern
Joined: 04 Sep 2009
Posts: 49
WE 1: Real estate investment consulting

Re: Survey yes/no
[#permalink]
Show Tags
20 Sep 2009, 04:13
barakhaiev wrote: Can anyone, please, explain, why result is E? And post OA. I am getting completely different result: 2/3N. If there are 1/4N people answered yes to q1 and 1/3 of those answered yes to q2. Thus, people who answered yes to q2 is 1/12. and total no of people ans yes is 1/12+1/4=1/3N.
So, those who answered NO: N1/3N=2/3N. What do I do wrong? help appreciated. One of the GMAT tricks. Do not overcomplicate  they ask for the mumber of people who did not answer "yes" to BOTH questions, while you are calculating "not yes for ANY of the 2 questions" E should be correct



Manager
Joined: 10 Jul 2009
Posts: 107
Location: Ukraine, Kyiv

Re: Survey yes/no
[#permalink]
Show Tags
22 Sep 2009, 11:52
arkadiyua wrote: barakhaiev wrote: Can anyone, please, explain, why result is E? And post OA. I am getting completely different result: 2/3N. If there are 1/4N people answered yes to q1 and 1/3 of those answered yes to q2. Thus, people who answered yes to q2 is 1/12. and total no of people ans yes is 1/12+1/4=1/3N.
So, those who answered NO: N1/3N=2/3N. What do I do wrong? help appreciated. One of the GMAT tricks. Do not overcomplicate  they ask for the mumber of people who did not answer "yes" to BOTH questions, while you are calculating "not yes for ANY of the 2 questions" E should be correct Ok, thanks. So does question asks (" of those") meaning of all people?
_________________
Never, never, never give up



Intern
Joined: 04 Sep 2009
Posts: 49
WE 1: Real estate investment consulting

Re: Survey yes/no
[#permalink]
Show Tags
22 Sep 2009, 12:56
barakhaiev wrote: Ok, thanks. So does question asks ("of those") meaning of all people? Nope. It's 1/3 of that 1/4 who answered yes to 1st question. The math goes like this: 1/4  yes to Q1 1/3 of 1/4  yes to Q2 and Q1. 1/3 of 1/4 is 1/12 of the total number of people The question asks simply how many people did are not included into that fraction, so we substract 1/12 from 1 as a whole, thus get 11/12



Manager
Joined: 10 Jul 2009
Posts: 107
Location: Ukraine, Kyiv

Re: Survey yes/no
[#permalink]
Show Tags
23 Sep 2009, 04:37
arkadiyua wrote: barakhaiev wrote: Ok, thanks. So does question asks ("of those") meaning of all people? Nope. It's 1/3 of that 1/4 who answered yes to 1st question. The math goes like this: 1/4  yes to Q1 1/3 of 1/4  yes to Q2 and Q1. 1/3 of 1/4 is 1/12 of the total number of people The question asks simply how many people did are not included into that fraction, so we substract 1/12 from 1 as a whole, thus get 11/12 I got it...tricky. Thank you very much for clarifying it, arkadiyua!
_________________
Never, never, never give up



Manager
Joined: 27 Oct 2008
Posts: 177

Re: Survey yes/no
[#permalink]
Show Tags
23 Sep 2009, 10:46
Yes i too go with the answer of 11N/12. The trick here is the number of people who have not answered YES to both questions is not the same as the number of people who have answered NO to both questions. It could be that they had answered YES to only one of the questions or NO to both questions.



Manager
Joined: 11 Sep 2009
Posts: 75

Re: Survey yes/no
[#permalink]
Show Tags
24 Oct 2009, 22:32
E for me
But this question is somewhat unclear to me. There might be people who answer no in the question 1 but answer yes in the question 2.



Director
Joined: 24 Aug 2007
Posts: 755
WE 1: 3.5 yrs IT
WE 2: 2.5 yrs Retail chain

Re: Survey yes/no
[#permalink]
Show Tags
11 May 2010, 07:29
I solved it in a different approach (with a calculated guess): N/4 says Yes to Q1. So, 3N/4 will say No to Q1.So, the final number has to be >=3N/4. On looking the choices B and E remains. We cant have 7 in the denominator, so E is the answer sudzpwc wrote: In a nationwide poll, N people were interviewed. If 1/4 of them answered "yes" to question 1, and of those, 1/3 answered "yes" to question 2, which of the following expressions represents the number of people interviewed who did NOT answer "yes" to both questions?
A N/7
B 6N/7
C 5N/12
D 7N/12
E 11N/12
_________________
Want to improve your CR: http://gmatclub.com/forum/crmethodsanapproachtofindthebestanswers93146.html Tricky Quant problems: http://gmatclub.com/forum/50trickyquestions92834.html Important Grammer Fundamentals: http://gmatclub.com/forum/keyfundamentalsofgrammerourcruciallearningsonsc93659.html



Manager
Joined: 08 May 2010
Posts: 129

Re: Survey yes/no
[#permalink]
Show Tags
19 May 2010, 19:30
So first we figure out what proportion of N did answer yes to both questions. 1/3 answered yes to #1 and of those 1/4 answered yes to #2. Thus 1/3 times 1/4=1/12N answered yes to both. Now it is simple subtraction to find those who did not vote yes on both. 11/12N. So the answer should be E.
If you found these comments helpful, please give kudos. Thanks, Skip



Director
Joined: 23 Apr 2010
Posts: 547

Re: Survey yes/no
[#permalink]
Show Tags
06 Oct 2010, 03:03
Bunuel, can you please look at this question. I personally got E for the answer. But after giving it some thought, I started to doubt it. My reasoning goes like this:
Total: 36
Yes to 1: 9 Yes to 1 and Yes to 2: 1/3 * 9 = 3
No to 1: 369 = 27 No to 1 No to 2: ? No to 1 Yes to 2: ?
So, I don't know how we can calculate No 1 No to 2. I guess that's what the question asks.
Thank you.



Director
Joined: 23 Apr 2010
Posts: 547

Re: Survey yes/no
[#permalink]
Show Tags
06 Oct 2010, 03:45
Yes, thanks a lot. I got the question wrong.



Senior Manager
Joined: 13 Aug 2012
Posts: 429
Concentration: Marketing, Finance
GPA: 3.23

Re: In a nationwide poll, N people were interviewed. If 1/4 of
[#permalink]
Show Tags
20 Dec 2012, 21:45
How many of N said yes to question 1? N/41/3 of that said Yes to question 2: N/12\(N  \frac{1}{4}*\frac{1}{3} = N  \frac{N}{12}= \frac{11N}{12}\) Answer: E
_________________
Impossible is nothing to God.



SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1825
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)

Re: In a nationwide poll, N people were interviewed. If 1/4 of
[#permalink]
Show Tags
24 Jul 2014, 00:50
We require to find the value of shaded region (in pink) Total students = n Yes for Q1 \(= \frac{n}{4}\) Yes for both Q1 & Q2\(= \frac{n}{4} * \frac{1}{3} = \frac{n}{12}\) Remaining\(= n  \frac{n}{12}\) \(= \frac{11n}{12}\) Answer = E
Attachments
pink.png [ 4.27 KiB  Viewed 23465 times ]
_________________
Kindly press "+1 Kudos" to appreciate



MBA Blogger
Joined: 19 Apr 2014
Posts: 90
Location: India
Concentration: Strategy, Technology
WE: Analyst (Computer Software)

In a nationwide poll, N people were interviewed. If 1/4 of
[#permalink]
Show Tags
02 Jan 2015, 01:38
I tried to do this question by making a table. But I was not able to get the answer!! have someone solved using table?     YQ1  NQ1    YQ2    NQ2   Total 
_________________
KUDOS please!! If it helped. Warm Regards. Visit My Blog



SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1825
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)

In a nationwide poll, N people were interviewed. If 1/4 of
[#permalink]
Show Tags
02 Jan 2015, 01:59
scofield1521 wrote: I tried to do this question by making a table. But I was not able to get the answer!! have someone solved using table?     YQ1  NQ1    YQ2    NQ2   Total  You require to change the row/column arrangement Refer diagram below: Attachment:
matrix.png [ 4.17 KiB  Viewed 6626 times ]
_________________
Kindly press "+1 Kudos" to appreciate




In a nationwide poll, N people were interviewed. If 1/4 of &nbs
[#permalink]
02 Jan 2015, 01:59



Go to page
1 2
Next
[ 31 posts ]



