Find all School-related info fast with the new School-Specific MBA Forum

It is currently 02 Sep 2015, 02:50
GMAT Club Tests

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Union of three sets formula derivation?

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Joined: 31 Dec 1969
Location: India
Concentration: Strategy, Operations
GMAT 1: 710 Q49 V0
GMAT 2: 740 Q40 V50
GMAT 3: 700 Q48 V38
GMAT 4: 710 Q45 V41
GPA: 4
WE: Sales (Investment Banking)
Followers: 0

Kudos [?]: 111 [0], given: 89813

Union of three sets formula derivation? [#permalink] New post 10 Jan 2012, 17:20
okay so i know the formula for this is:
P(A) + P(B) + P(C) - P(AnB) - P(AnC) - P(BnC) + P(AnBnC)
but i literally do not understand how to get the P(AnBnC)
can someone please beak it down for me :| ?
Expert Post
1 KUDOS received
Kaplan GMAT Instructor
User avatar
Joined: 25 Aug 2009
Posts: 644
Location: Cambridge, MA
Followers: 73

Kudos [?]: 215 [1] , given: 2

Re: Union of three sets formula derivation? [#permalink] New post 10 Jan 2012, 19:10
1
This post received
KUDOS
Expert's post
Let's suppose an object X is in A, B, and C.

Since you are counting A, B, and C serparately, you've counted X three times.

But then, you subtract everything in A & B, B & C, and A & C. X is in each of those, so you've subtracted X three times. That means you haven't actually counted X.

So, you need to add X (and every other object in A, B, and C) to get the correct total, because otherwise you aren't counting it.
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save $150 on a course!

Image

Kaplan Reviews

Re: Union of three sets formula derivation?   [#permalink] 10 Jan 2012, 19:10
    Similar topics Author Replies Last post
Similar
Topics:
5 Experts publish their posts in the topic What is Test set? haihai89 1 24 Oct 2014, 01:31
Equations for 3 overlapping sets makhija1 1 21 Jun 2013, 20:28
Experts publish their posts in the topic Issues with Overlapping sets deliverance 1 12 Aug 2012, 03:01
Questions on overalpping sets & geometry GMATPASSION 0 25 Nov 2011, 17:41
Experts publish their posts in the topic Taking derivatives on GMAT questions stringworm 2 14 Nov 2011, 10:55
Display posts from previous: Sort by

Union of three sets formula derivation?

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

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®.