GMAT Changed on April 16th - Read about the latest changes here

It is currently 20 May 2018, 16:41

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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

The probability that event A occurs is 0.4, and the probabil

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

3 KUDOS received
Senior Manager
Senior Manager
avatar
Status: Do and Die!!
Joined: 15 Sep 2010
Posts: 288
The probability that event A occurs is 0.4, and the probabil [#permalink]

Show Tags

New post Updated on: 28 Mar 2018, 04:13
3
This post received
KUDOS
6
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

78% (01:00) correct 22% (01:35) wrong based on 286 sessions

HideShow timer Statistics

The probability that event A occurs is 0.4, and the probability that events A and B both occur is 0.25. If the probability that either event A or event B occurs is 0.6, what is the probability that event B will occur?

A. 0.05
B. 0.15
C. 0.45
D. 0.50
E. 0.55
[Reveal] Spoiler: OA

_________________

I'm the Dumbest of All !!


Originally posted by shrive555 on 26 Dec 2010, 18:47.
Last edited by abhimahna on 28 Mar 2018, 04:13, edited 1 time in total.
Edited the question
1 KUDOS received
Retired Moderator
avatar
Joined: 03 Aug 2010
Posts: 221
Re: The probability that event A occurs is 0.4, and the probabil [#permalink]

Show Tags

New post 26 Dec 2010, 21:42
1
This post received
KUDOS
1
This post was
BOOKMARKED
P(A or B) = P (A) + P(B) - p(a n b)
0.6= 0.4 + P(B) - 0.25
P(B) = 0.45
_________________

http://www.gmatpill.com/gmat-practice-test/

Amazing Platform

1 KUDOS received
Manager
Manager
avatar
Joined: 31 May 2010
Posts: 83
Reviews Badge
Re: The probability that event A occurs is 0.4, and the probabil [#permalink]

Show Tags

New post 26 Dec 2010, 23:30
1
This post received
KUDOS
P(AandB) = pA + pB - p(AintersectionB)
0.6= 0.4 + p(B) - 0.25
= 0.45
_________________

Kudos if any of my post helps you !!!

Manager
Manager
avatar
Status: UC Berkeley 2012
Joined: 03 Jul 2010
Posts: 161
Location: United States
Concentration: Economics, Finance
GPA: 4
WE: Consulting (Investment Banking)
GMAT ToolKit User
Re: The probability that event A occurs is 0.4, and the probabil [#permalink]

Show Tags

New post 27 Dec 2010, 03:29
1
This post was
BOOKMARKED
you can state both equations only if they are independent from each other ...
Manager
Manager
avatar
Joined: 30 May 2013
Posts: 168
Location: India
Concentration: Entrepreneurship, General Management
GPA: 3.82
GMAT ToolKit User
Re: The probability that event A occurs is 0.4, and the probabil [#permalink]

Show Tags

New post 10 Aug 2013, 05:33
hirendhanak wrote:
P(A or B) = P (A) + P(B) - p(a n b)
0.6= 0.4 + P(B) - 0.25
P(B) = 0.45



Hi.

Can u tell me wat is P(AandB)????

Please clear my doubt.

regards,
Rrsnathan.
1 KUDOS received
VP
VP
User avatar
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1101
Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
GMAT ToolKit User
Re: The probability that event A occurs is 0.4, and the probabil [#permalink]

Show Tags

New post 10 Aug 2013, 05:59
1
This post received
KUDOS
rrsnathan wrote:
hirendhanak wrote:
P(A or B) = P (A) + P(B) - p(a n b)
0.6= 0.4 + P(B) - 0.25
P(B) = 0.45



Hi.

Can u tell me wat is P(AandB)????

Please clear my doubt.

regards,
Rrsnathan.


P(A and B)= probability both events (A,B) occur= P(A)*P(B).

Hope this clear your doubt
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

Senior Manager
Senior Manager
avatar
Joined: 10 Jul 2013
Posts: 318
Re: The probability that event A occurs is 0.4, and the probabil [#permalink]

Show Tags

New post 10 Aug 2013, 14:10
shrive555 wrote:
The probability that event A occurs is 0.4, and the probability that events A and B both occur is 0.25. If the probability that either event A or event B occurs is 0.6, what is the probability that event B will occur?

0.05
0.15
0.45
0.50
0.55


P(A) = .40
P(A and B) = P(A) * P(B) = .25 ----1
P(A or B) = P (A) + P(B) = .60 -----2

Both 1 & 2 give different results.
1 => P(B) = \(.25/P(A)\) = 0.62
2=> P(B) = .60 - .40 = .20

whats going wrong ...i don;t know :roll:

The only correction you need is to minus...
P(A or B) = P (A) + P(B) - P(A) * P(B) =
or, 0.60 = 0.4 +p(B) - 0.25
so, p(B) = 0.45 (C)

we all make mistake....don't worry about it... :)
_________________

Asif vai.....

Director
Director
avatar
S
Joined: 12 Nov 2016
Posts: 778
Location: United States
Schools: Yale '18
GMAT 1: 650 Q43 V37
GRE 1: 315 Q157 V158
GPA: 2.66
Re: The probability that event A occurs is 0.4, and the probabil [#permalink]

Show Tags

New post 12 Oct 2017, 20:30
shrive555 wrote:
The probability that event A occurs is 0.4, and the probability that events A and B both occur is 0.25. If the probability that either event A or event B occurs is 0.6, what is the probability that event B will occur?

A. 0.05
B. 0.15
C. 0.45
D. 0.50
E. 0.55


P(A) = .40
P(A and B) = P(A) * P(B) = .25 ----1
P(A or B) = P (A) + P(B) = .60 -----2

Both 1 & 2 give different results.
1 => P(B) = \(.25/P(A)\) = 0.62
2=> P(B) = .60 - .40 = .20

whats going wrong ...i don;t know :roll:


If A and B are overlapping events then

P (A or B) = P(A) + P(B) - P(A and B)

C
Director
Director
avatar
S
Joined: 12 Nov 2016
Posts: 778
Location: United States
Schools: Yale '18
GMAT 1: 650 Q43 V37
GRE 1: 315 Q157 V158
GPA: 2.66
Re: The probability that event A occurs is 0.4, and the probabil [#permalink]

Show Tags

New post 12 Oct 2017, 20:36
shrive555 wrote:
The probability that event A occurs is 0.4, and the probability that events A and B both occur is 0.25. If the probability that either event A or event B occurs is 0.6, what is the probability that event B will occur?

A. 0.05
B. 0.15
C. 0.45
D. 0.50
E. 0.55


P(A) = .40
P(A and B) = P(A) * P(B) = .25 ----1
P(A or B) = P (A) + P(B) = .60 -----2

Both 1 & 2 give different results.
1 => P(B) = \(.25/P(A)\) = 0.62
2=> P(B) = .60 - .40 = .20

whats going wrong ...i don;t know :roll:


Another way of looking at this is that both events are overlapping events- A and B can occur at the same time - this is basically the same as

Total= A + B -both --> is the same thing as saying P(A or B)= P(A) + P(B) -P(A and B)

This is one application of the overlapping set formula to probability
Re: The probability that event A occurs is 0.4, and the probabil   [#permalink] 12 Oct 2017, 20:36
Display posts from previous: Sort by

The probability that event A occurs is 0.4, and the probabil

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.