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:

Of the 500 business people surveyed, 78 percent said that [#permalink]

Show Tags

01 Dec 2012, 02:11

2

This post received KUDOS

1

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

5% (low)

Question Stats:

92% (02:07) correct
8% (01:43) wrong based on 136 sessions

HideShow timer Statistics

Of the 500 business people surveyed, 78 percent said that they use their laptop computers at home, 65 percent said that they use them in hotels, and 52 percent said that they use them both at home and in hotels. How many of the business people surveyed said that they do not use their laptop computers either at home or in hotels?

Can somebody give the formula for this overlapping set problem? P(AUB) = P(A)+P(B)-P(A intersection B) I tried to use the domain matrix learnt from MGMAT. But somewhere I am going wrong, can someone help?

Of the 500 business people surveyed, 78 percent said that they use their laptop computers at home, 65 percent said that they use them in hotels, and 52 percent said that they use them both at home and in hotels. How many of the business people surveyed said that they do not use their laptop computers either at home or in hotels?

Can somebody give the formula for this overlapping set problem? P(AUB) = P(A)+P(B)-P(A intersection B) I tried to use the domain matrix learnt from MGMAT. But somewhere I am going wrong, can someone help?

I guess you made a mathematical error. Personally, I prefer creating the matrix in percentages when the question is given in percentages. And finally multiply what I want with the total. However for illustration the matrix should be

Attachments

Untitled.png [ 9.56 KiB | Viewed 3912 times ]

_________________

Did you find this post helpful?... Please let me know through the Kudos button.

No reason to use formulas or weird pictures for this problem. Just think about what each set is.

I took the totals: 390 people use their laptop at home [1] 325 people use their laptop in hotels [2] 260 people use their laptop both in hotels and at home [3]

Clearly if someone uses their laptop both in hotels and at home, they belong in both the previous two sets (1,2). By subtracting set 3 from the first two, we can determine the number of people that lie in set 1 or set 2 but not in set 3.

Gives us: 130 only use their laptop at home 65 only use their laptop in hotels 260 use their laptop in both

add them up, subtract from the total and you get 45.

Re: Of the 500 business people surveyed, 78 percent said that [#permalink]

Show Tags

23 Oct 2013, 15:40

3

This post received KUDOS

I kept everything in percentage form since that is how the information was presented. I did not want to introduce calculations that could lead to an error.

I used the group formula:

Total = Group 1 + Group 2 - Both + Neither.

Using the formula above and the information we are given:

100% = 78% + 65% - 52% + Neither

100% = 91% + Neither or

Neither = 100% - 91% = 9%

The total here is 500 so we can multiply 9% with 500 to get the amount of business people who do no use their laptops at home or in hotels.

(9/100) * 500 = 45

All of the methods mentioned above work, but I hope someone finds this helpful too. We can never have too many ways to approach a problem.

Re: Of the 500 business people surveyed, 78 percent said that [#permalink]

Show Tags

08 Dec 2014, 13:33

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: Of the 500 business people surveyed, 78 percent said that [#permalink]

Show Tags

21 Nov 2015, 21:26

I used a chart like other people but left everything in percents and then calculated 9% of 500 = 45. I've found that the GMAT rewards you for procrastinating on doing calculations.

gmatclubot

Re: Of the 500 business people surveyed, 78 percent said that
[#permalink]
21 Nov 2015, 21:26

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)...