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.

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 data company recently conducted a survey to determine wh [#permalink]
08 Jun 2013, 01:11

1

This post received KUDOS

1

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

25% (medium)

Question Stats:

70% (01:59) correct
30% (01:00) wrong based on 120 sessions

A data company recently conducted a survey to determine whether people use product X or product Y. If fewer than 100 people were surveyed and each person used either one product or both, how many people used product Y?

(1) 65% of survey respondents used only product X (2) 10% of survey respondents used both products X and Y

Re: A data company recently conducted a survey to determine wh [#permalink]
08 Jun 2013, 02:03

Expert's post

A data company recently conducted a survey to determine whether people use product X or product Y. If fewer than 100 people were surveyed and each person used either one product or both, how many people used product Y?

Given: {Total} < 100 and {Neither} = 0.

{Total} = {Only X} + {Only Y} + {Both}. Notice that this formula is different from {Total} = {X} + {Y} - {Both}.

(1) 65% of survey respondents used only product X. 65%=65/100=13/20, thus {Total} must be a multiple of 20. Not sufficient.

(2) 10% of survey respondents used both products X and Y. 10%=1/10, thus {Total} must be a multiple of 20. Not sufficient.

(1)+(2) If {Total} = 20, then {Only X} = 13/20*20 = 13, thus {Y} = {Total} - {Only X} = 7 BUT {Total} = 40, then {Only X} = 13/20*40 = 26, thus {Y} = {Total} - {Only X} = 14. Not sufficient.

Re: A data company recently conducted a survey to determine wh [#permalink]
08 Jun 2013, 17:28

emmak wrote:

A data company recently conducted a survey to determine whether people use product X or product Y. If fewer than 100 people were surveyed and each person used either one product or both, how many people used product Y?

(1) 65% of survey respondents used only product X (2) 10% of survey respondents used both products X and Y

Just pick good numbers to fill in the answers , lets say 80 or 60. Each time with the given fact you will get a different answer.Hence E.

Given less than 100 people were surveyed St 1. X = less than 65 Does not tell anything about Y Not-Suff St. 2 Both = less than 10 - Not Suff

Together : Can be multiple ans for Y

Ans : E

Another way to look at this question . Total given is a range.Total can be any number from 1 to 99 ( total <100). (1) X is 65% of Total => X can have multiple values as total is not fixed => Not Sufficient .Unable to get a single value for Y (2)Both X & Y = 10% of Total => multiple values => Not Sufficient .Unable to get a single value for Y

(1) & (2) together also does not help to get a single value for Y.Hence answer is E

Given less than 100 people were surveyed St 1. X = less than 65 Does not tell anything about Y Not-Suff St. 2 Both = less than 10 - Not Suff

Together : Can be multiple ans for Y

Ans : E

Another way to look at this question . Total given is a range.Total can be any number from 1 to 99 ( total <100). (1) X is 65% of Total => X can have multiple values as total is not fixed => Not Sufficient .Unable to get a single value for Y (2)Both X & Y = 10% of Total => multiple values => Not Sufficient .Unable to get a single value for Y

(1) & (2) together also does not help to get a single value for Y.Hence answer is E

it's a one line solution problem. we know just one thing and it's less than 100 people, 1 to 99 anything . 99cases not only double cases.. so its not possible to evaluate how many people used Y or X or anything else, just by using % . so (E) _________________

Re: A data company recently conducted a survey to determine wh [#permalink]
20 Sep 2013, 17:27

I'd disagree with the suggested answer.

The answer should actually be A.

The question asks how many people use Y, not 'only' Y. So it should be the total of the # people who use only Y + the # of people who use Y and X.

If 65% of respondents used only X. And less than 100 people were surveyed, we know that the number of people who used only X must be a variable of a factor of 65 since only whole people (integers) can fit into a bucket.

Since every responder must choose one or both products and neither is not an option we know that 35% use Y.

65 and 35 are both only divisible by 5. Therefore 13 people use only X and 7 use Y or both. Therefore the answer should be A as we can determine the value is 7.

Re: A data company recently conducted a survey to determine wh [#permalink]
21 Sep 2013, 02:33

Expert's post

thatgmat wrote:

I'd disagree with the suggested answer.

The answer should actually be A.

The question asks how many people use Y, not 'only' Y. So it should be the total of the # people who use only Y + the # of people who use Y and X.

If 65% of respondents used only X. And less than 100 people were surveyed, we know that the number of people who used only X must be a variable of a factor of 65 since only whole people (integers) can fit into a bucket.

Since every responder must choose one or both products and neither is not an option we know that 35% use Y.

65 and 35 are both only divisible by 5. Therefore 13 people use only X and 7 use Y or both. Therefore the answer should be A as we can determine the value is 7.

Re: A data company recently conducted a survey to determine wh [#permalink]
22 Sep 2013, 12:09

Bunuel wrote:

A data company recently conducted a survey to determine whether people use product X or product Y. If fewer than 100 people were surveyed and each person used either one product or both, how many people used product Y?

Given: {Total} < 100 and {Neither} = 0.

{Total} = {Only X} + {Only Y} + {Both}. Notice that this formula is different from {Total} = {X} + {Y} - {Both}.

Bunuel,

what's the difference between the two formulas? when would we use the second one? thanks

Re: A data company recently conducted a survey to determine wh [#permalink]
22 Sep 2013, 22:44

Expert's post

LinaNY wrote:

Bunuel wrote:

A data company recently conducted a survey to determine whether people use product X or product Y. If fewer than 100 people were surveyed and each person used either one product or both, how many people used product Y?

Given: {Total} < 100 and {Neither} = 0.

{Total} = {Only X} + {Only Y} + {Both}. Notice that this formula is different from {Total} = {X} + {Y} - {Both}.

Bunuel,

what's the difference between the two formulas? when would we use the second one? thanks

The two formulas are:

{Total} = {X} + {Y} - {Both} + {Neither}

Now, since {X} = {Only X} + {Both} and {Y} = {Only Y} + {Both}, then if you substitute you get: {Total} = {Only X} + {Only Y} + {Both} + {Neither}

You should apply the one which best suits the question at hand. _________________