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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

A manufacturer conducted a survey to determine how many peop [#permalink]

Show Tags

10 Dec 2010, 12:32

1

This post received KUDOS

9

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

15% (low)

Question Stats:

72% (01:41) correct
28% (00:45) wrong based on 326 sessions

HideShow timer Statistics

A manufacturer conducted a survey to determine how many people buy products P and Q. What fraction of the people surveyed said that they buy neither product P nor product Q?

(1) 1/3 of the people surveyed said that they buy product P but not product Q. (2) 1/2 of the people surveyed said that they buy product Q.

A manufacturer conducted a survey to determine how many peop [#permalink]

Show Tags

10 Dec 2010, 13:01

7

This post received KUDOS

Expert's post

2

This post was BOOKMARKED

A manufacturer conducted a survey to determine how many people buy products P and Q. What fraction of the people surveyed said that they buy neither product P nor product Q?

You can solve this question with Venn diagram, matrix or as shown below.

{Total} = {buy P} + {buy Q} - {buy both P and Q} + {buy neither P nor Q}. Question: {buy neither P nor Q} / {Total} = ?

Take total to be equal to 6 (as it's a multiple of both 2 and 3)

(1) 1/3 of the people surveyed said that they buy product P but not product Q:

{buy P} - {buy both P and Q} = 1/3*6 = 2; 6 = {buy P} + {buy Q} - ({buy P} - 2) + {buy neither P nor Q} 4={buy Q} + {buy neither P nor Q}.

Not sufficient to get the ratio we need.

(2) 1/2 of the people surveyed said that they buy product Q:

{buy Q}=1/2*6=3. Not sufficient.

(1)+(2) 4={buy Q} + {buy neither P nor Q} and {buy Q} = 3; {buy neither P nor Q} = 1; {buy neither P nor Q}/{Total} = 1/6. Sufficient.

There are 2 products "P" and "Q", and we have to answer what fraction of people do not select both the products.

Option 1- 1/3 of people select only P and not Q So, suppose we have 90 people responded to survey then 1/3 of 90 = 30 people select only product P But, this option does not tells us anything about Q, so not sufficient to answer the question.

Option 2- 1/2 people select product Q ....this includes people who selected inly product Q and people who selected both product P and Q i.e. P intersection Q Therefore if 90 people responded to survey 45 people selected product Q, but it does not tells us how many people select only product p

Now, it we combine the options it gives us value of A U B i.e if we have 90 people on the survey 30 selected product P and 45 selected product Q along with P intersection Q

Therefore P U Q = 30 + 45 = 75 Therefore (P U Q)' = 90 - 75 = 15 Hence fraction of people did not select any product = 15/90

Hence we get the answer by taking both the options together... hence answer "C"

1. the total is 6. (1) means we have 2 ppl buy product P no Q. (2) means 3 ppl buy Q (mayb together with P also). i still cannot understand how u can figure out from that the area covered by both P+Q and by none. Im not sure what im missing, but as i see it, we can have ppl that buy both P+Q between none to 4 and it still wont make any logic problem with both sentences.

I guess im having hard time to understand why u chose to put the - {buy both P and Q} in minus and not plus. the total should be a sum of all groups together isnt it?

thanks a lot for all the time and help for both of u guys. _________________

1. the total is 6. (1) means we have 2 ppl buy product P no Q. (2) means 3 ppl buy Q (mayb together with P also). i still cannot understand how u can figure out from that the area covered by both P+Q and by none. Im not sure what im missing, but as i see it, we can have ppl that buy both P+Q between none to 4 and it still wont make any logic problem with both sentences.

I guess im having hard time to understand why u chose to put the - {buy both P and Q} in minus and not plus. the total should be a sum of all groups together isnt it?

thanks a lot for all the time and help for both of u guys.

Venn diagram makes this question MUCH easier:

Attachment:

untitled.PNG [ 7.28 KiB | Viewed 11096 times ]

First about the formula:{Total} = {buy P} + {buy Q} - {buy both P and Q} + {buy neither P nor Q}. Note that P={Only P}+{Both P&Q} and Q={Only Q}+{Both P&Q}. In {Total}={P}+{Q}-{Both P&Q}+{Neither P nor Q} we subtract {Both P&Q} as P and Q both contain this segment and thus in P+Q it's counted twice, so we should subtract it to count it only once.

Back to the question:

Again let's take total to be equal to 6: so 6=Green+Yellow+Blue+Grey. We need to get Grey/Total=Grey/6=?.

(1) 1/3 of the people surveyed said that they buy product P but not product Q --> Green=1/3*6=2. Not sufficient to get the ratio we need.

(2) 1/2 of the people surveyed said that they buy product Q --> Yellow+Blue=1/2*6=3. Not sufficient.

I guess im having hard time to understand why u chose to put the - {buy both P and Q} in minus and not plus. the total should be a sum of all groups together isnt it?

thanks a lot for all the time and help for both of u guys.

Here's the equation:

True # of objects = (everyone in group 1) + (everyone in group 2) - (everyone in both groups) + people in neither group

You ask why we subtract everyone in both groups; it's because we've already counted those people twice!

If we break down the first two components

everyone in group 1 = (people only in group 1) + (people in both groups) everyone in group 2 = (people only in group 2) + (people in both groups)

you can see that we've counted "people in both groups" twice. Subbing into the original equation:

True # of objects = ((people only in group 1) + (people in both groups)) + ((people only in group 2) + (people in both groups)) - (everyone in both groups) + people in neither group

which is why we need to subtract "everyone in both groups" to end up only counting them once.

With the Venn Diagram it makes sense but writing it out algabreically I wouldn't be able to do it I would get as far as this and wouldn't know how to figure out both the only Q and both values. I think I am missing a simple implication of the 2nd statement and what affect it has.

Total= P + Q -both +neither 6= 2+ _________________

With the Venn Diagram it makes sense but writing it out algabreically I wouldn't be able to do it I would get as far as this and wouldn't know how to figure out both the only Q and both values. I think I am missing a simple implication of the 2nd statement and what affect it has.

Re: A manufacturer conducted a survey to determine how many peop [#permalink]

Show Tags

21 Sep 2014, 12:50

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. _________________

Re: A manufacturer conducted a survey to determine how many peop [#permalink]

Show Tags

22 Jul 2015, 05:06

Bunuel wrote:

A manufacturer conducted a survey to determine how many people buy products P and Q. What fraction of the people surveyed said that they buy neither product P nor product Q?

You can solve this question with Venn diagram, matrix or as shown below.

{Total} = {buy P} + {buy Q} - {buy both P and Q} + {buy neither P nor Q}. Question: {buy neither P nor Q} / {Total} = ?

Take total to be equal to 6 (as it's a multiple of both 2 and 3)

(1) 1/3 of the people surveyed said that they buy product P but not product Q --> {buy P} - {buy both P and Q}=1/3*6=2 --> 6 = {buy P} + {buy Q} - ({buy P} - 2) + {buy neither P nor Q} --> 4={buy Q} + {buy neither P nor Q}. Not sufficient to get the ratio we need.

(2) 1/2 of the people surveyed said that they buy product Q --> {buy Q}=1/2*6=3. Not sufficient.

(1)+(2) 4={buy Q} + {buy neither P nor Q} and {buy Q}=3 --> {buy neither P nor Q}=1 --> {buy neither P nor Q}/{Total}=1/6. Sufficient.

Answer: C.

i could solve the que with help of ven dia. but i am unable to understand the highlighted portion of explanation. pls help.

Re: A manufacturer conducted a survey to determine how many peop [#permalink]

Show Tags

22 Jul 2015, 05:45

Expert's post

riyazgilani wrote:

Bunuel wrote:

A manufacturer conducted a survey to determine how many people buy products P and Q. What fraction of the people surveyed said that they buy neither product P nor product Q?

You can solve this question with Venn diagram, matrix or as shown below.

{Total} = {buy P} + {buy Q} - {buy both P and Q} + {buy neither P nor Q}. Question: {buy neither P nor Q} / {Total} = ?

Take total to be equal to 6 (as it's a multiple of both 2 and 3)

(1) 1/3 of the people surveyed said that they buy product P but not product Q --> {buy P} - {buy both P and Q}=1/3*6=2 --> 6 = {buy P} + {buy Q} - ({buy P} - 2) + {buy neither P nor Q} --> 4={buy Q} + {buy neither P nor Q}. Not sufficient to get the ratio we need.

(2) 1/2 of the people surveyed said that they buy product Q --> {buy Q}=1/2*6=3. Not sufficient.

(1)+(2) 4={buy Q} + {buy neither P nor Q} and {buy Q}=3 --> {buy neither P nor Q}=1 --> {buy neither P nor Q}/{Total}=1/6. Sufficient.

Answer: C.

i could solve the que with help of ven dia. but i am unable to understand the highlighted portion of explanation. pls help.

{Total} = {buy P} + {buy Q} - {buy both P and Q} + {buy neither P nor Q}.

From (1): {buy P} - {buy both P and Q} = 1/3*6 = 2, so {buy both P and Q} = {buy P} - 2.

Substitute in above: 6 = {buy P} + {buy Q} - ({buy P} - 2) + {buy neither P nor Q} _________________

Re: A manufacturer conducted a survey to determine how many peop [#permalink]

Show Tags

05 Sep 2015, 09:59

vyassaptarashi wrote:

This problem should be solved following way

There are 2 products "P" and "Q", and we have to answer what fraction of people do not select both the products.

Option 1- 1/3 of people select only P and not Q So, suppose we have 90 people responded to survey then 1/3 of 90 = 30 people select only product P But, this option does not tells us anything about Q, so not sufficient to answer the question.

Option 2- 1/2 people select product Q ....this includes people who selected inly product Q and people who selected both product P and Q i.e. P intersection Q Therefore if 90 people responded to survey 45 people selected product Q, but it does not tells us how many people select only product p

Now, it we combine the options it gives us value of A U B i.e if we have 90 people on the survey 30 selected product P and 45 selected product Q along with P intersection Q

Therefore P U Q = 30 + 45 = 75 Therefore (P U Q)' = 90 - 75 = 15 Hence fraction of people did not select any product = 15/90

Hence we get the answer by taking both the options together... hence answer "C"

I find this solution WAY more intuitive, big thanks _________________

A manufacturer conducted a survey to determine how many peop [#permalink]

Show Tags

05 Sep 2015, 22:52

Expert's post

Forget conventional ways of solving math questions. In DS, Variable approach is

the easiest and quickest way to find the answer without actually solving the

problem. Remember equal number of variables and equations ensures a solution.

A manufacturer conducted a survey to determine how many people buy products P and Q. What fraction of the people surveyed said that they buy neither product P nor product Q?

(1) 1/3 of the people surveyed said that they buy product P but not product Q. (2) 1/2 of the people surveyed said that they buy product Q.

==> this is a common 2by2 question in GMAT tests that we use variable approach method to solve.

as we can see from above, the original condition is asking for d and since we have 4 variables (a,b,c,d), we need 4 equations to match the number of variables and equations. Since we have 1 each in 1) and 2), E is likely the answer. Using both 1) and 2) together, c=1/3 and a+b=1/2 thus we have c+d=1/2. substituting c=1/3 gives us d=1/6, therefore the answer is C. Here we were able to find the answer, but normally for 90% of these questions with 4 variables the the answer is E. This case was a special case.

Attachments

GC DS 144144 A manufacture conducted (20150905).jpg [ 23.75 KiB | Viewed 3324 times ]

Re: A manufacturer conducted a survey to determine how many peop [#permalink]

Show Tags

08 Dec 2015, 02:12

Bunuel wrote:

A manufacturer conducted a survey to determine how many people buy products P and Q. What fraction of the people surveyed said that they buy neither product P nor product Q?

You can solve this question with Venn diagram, matrix or as shown below.

{Total} = {buy P} + {buy Q} - {buy both P and Q} + {buy neither P nor Q}. Question: {buy neither P nor Q} / {Total} = ?

Take total to be equal to 6 (as it's a multiple of both 2 and 3)

(1) 1/3 of the people surveyed said that they buy product P but not product Q:

{buy P} - {buy both P and Q} = 1/3*6 = 2; 6 = {buy P} + {buy Q} - ({buy P} - 2) + {buy neither P nor Q} 4={buy Q} + {buy neither P nor Q}.

Not sufficient to get the ratio we need.

(2) 1/2 of the people surveyed said that they buy product Q:

{buy Q}=1/2*6=3. Not sufficient.

(1)+(2) 4={buy Q} + {buy neither P nor Q} and {buy Q} = 3; {buy neither P nor Q} = 1; {buy neither P nor Q}/{Total} = 1/6. Sufficient.

Answer: C.

Hi Bunuel,

I have a query on st1.

1/3 of the people surveyed said that they buy product P but not product Q

can we infer from above statement 2/3 of people surveyed said they buy product P and product Q.

Excellent posts dLo saw your blog too..!! Man .. you have got some writing skills. And Just to make an argument = You had such an amazing resume ; i am glad...

So Much $$$ Business school costs a lot. This is obvious, whether you are a full-ride scholarship student or are paying fully out-of-pocket. Aside from the (constantly rising)...

I barely remember taking decent rest in the last 60 hours. It’s been relentless with submissions, birthday celebration, exams, vacating the flat, meeting people before leaving and of...

Rishabh from Gyan one services, India had a one to one interview with me where I shared my experience at IMD till now. http://www.gyanone.com/blog/life-at-imd-interview-with-imd-mba/ ...