Last visit was: 19 Nov 2025, 09:51 It is currently 19 Nov 2025, 09:51
Home
GMAT
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
avatar
pmenon
avatar
Joined: 28 Dec 2005
Last visit: 01 Jul 2009
Posts: 692
Own Kudos:
600
Given Kudos: 2
Posts: 692
Kudos: 600
If the probability is 0.6 that stock A will increase in 17 Nov 2007, 10:27
Kudos
Add Kudos
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
N
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

(N/A)

Question Stats:

89% (00:47) correct 11% (00:50) wrong based on 113 sessions

History

Date
Time
Result
Not Attempted Yet
If the probability is 0.6 that stock A will increase in value during the next month and the probability is 0.4 that stock B will increase in value during the next month, what is the greatest possible value for the probability that neither of these two events will occur?

A) 0.20

B) 0.24

C) 0.40

D) 0.46

E) 0.60



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
User avatar
KillerSquirrel
User avatar
Joined: 08 Jun 2005
Last visit: 28 Mar 2009
Posts: 520
Own Kudos:
634
Posts: 520
Kudos: 634
If the probability is 0.6 that stock A will increase in 17 Nov 2007, 10:36
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Stock A = 3/5
Stock B = 2/5

not A & not B = 2/5*3/5 = 6/25

A & not B = 3/5*3/5 = 9/25

B & not A = 2/5*2/5 = 4/25

total

1 - 19/25 = 6/25

the answer is (B)

:)
User avatar
GK_Gmat
User avatar
Joined: 09 Aug 2006
Last visit: 28 Feb 2009
Posts: 348
Own Kudos:
1,061
Posts: 348
Kudos: 1,061
If the probability is 0.6 that stock A will increase in 17 Nov 2007, 10:42
Kudos
Add Kudos
Bookmarks
Bookmark this Post
pmenon
If the probability is 0.6 that stock A will increase in value during the next month and the probability is 0.4 that stock B will increase in value during the next month, what is the greatest possible value for the probability that neither of these two events will occur?

A) 0.20

B) 0.24

C) 0.40

D) 0.46

E) 0.60
Show more


p(A will not rise) = .4
p(B will not rise) = .6
p (A will not rise & B will not rise) = .6 * .4 = .24

Answer B
avatar
pmenon
avatar
Joined: 28 Dec 2005
Last visit: 01 Jul 2009
Posts: 692
Own Kudos:
600
Given Kudos: 2
Posts: 692
Kudos: 600
If the probability is 0.6 that stock A will increase in 17 Nov 2007, 12:48
Kudos
Add Kudos
Bookmarks
Bookmark this Post
i had the exact same answer, but another forum is saying that the answer is 0.4 .... i dont think this is right, and feel even more confident after KillerSquirrel answered as 0.24 :)
User avatar
Ravshonbek
User avatar
Joined: 09 Jul 2007
Last visit: 15 Jul 2008
Posts: 565
Own Kudos:
571
Location: London
Posts: 565
Kudos: 571
If the probability is 0.6 that stock A will increase in 17 Nov 2007, 12:51
Kudos
Add Kudos
Bookmarks
Bookmark this Post
which forum is it? testmagic? or scorechase?
avatar
xanados
avatar
Joined: 15 Jun 2009
Last visit: 16 Jun 2009
Posts: 1
Posts: 1
Kudos: 0
If the probability is 0.6 that stock A will increase in 16 Jun 2009, 18:04
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The argument for 0.4 stems from the question of whether the two stocks are independent or not. The question doesn't say whether they are independent, and, as most people understand, stocks tend to move together. If the answer is in fact 0.24, then the question should be more explicit, or should not use stocks as the example.

The 0.4 represents the maximum possible probability if the two events are dependent in some fashion.
avatar
srivas
avatar
Joined: 27 Oct 2008
Last visit: 28 Sep 2009
Posts: 95
Own Kudos:
310
Given Kudos: 3
Posts: 95
Kudos: 310
If the probability is 0.6 that stock A will increase in 28 Sep 2009, 04:03
Kudos
Add Kudos
Bookmarks
Bookmark this Post
If the probability is 0.6 that stock A will increase in value during the next month and the probability is 0.4 that stock B will increase in value during the next month, what is the greatest possible value for the probability that neither of these two events will occur?

A) 0.20

B) 0.24

C) 0.40

D) 0.46

E) 0.60


Soln:
= (1-P(A) * (1-P(B))
= .4 * .6
=.24

Ans is B



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
Moderator:
Bunuel
Math Expert
105389 posts