January 26, 2019 January 26, 2019 07:00 AM PST 09:00 AM PST Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions. January 27, 2019 January 27, 2019 07:00 AM PST 09:00 AM PST Attend this webinar to learn a structured approach to solve 700+ Number Properties question in less than 2 minutes.
Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 10 Feb 2011
Posts: 108

What is the probability that event E or event F or both will
[#permalink]
Show Tags
01 Mar 2011, 09:57
Question Stats:
51% (00:46) correct 49% (00:49) wrong based on 463 sessions
HideShow timer Statistics
What is the probability that event E or event F or both will occur? (1) The probability that event E will occur is 0.6. (2) The probability that event F will occur is 0.4.
Official Answer and Stats are available only to registered users. Register/ Login.



Director
Status: Impossible is not a fact. It's an opinion. It's a dare. Impossible is nothing.
Affiliations: University of Chicago Booth School of Business
Joined: 03 Feb 2011
Posts: 728

Re: : What is the probability that event E or event F or both w
[#permalink]
Show Tags
01 Mar 2011, 10:19
Yeah it hit me. P(E) + P(F) =1.0 This means the overlap is unknown. P(E and F) has to be known to solve this scenario. Hence E



Manager
Joined: 14 Feb 2011
Posts: 175

Re: : What is the probability that event E or event F or both w
[#permalink]
Show Tags
01 Mar 2011, 10:21
We do not know whether events E & F are independent events, so can't conclude anything from given information in either 1) or 2), Hence E



Manager
Joined: 24 Nov 2010
Posts: 177
Location: United States (CA)
Concentration: Technology, Entrepreneurship

Re: : What is the probability that event E or event F or both w
[#permalink]
Show Tags
01 Mar 2011, 10:33
The Ans will be E as it is not specified that the events are mutually exclusive.
If the events are mutually exclusive then the prob = 0
However, if there is an overlap, then we'd need the prob of e & f happening together to calculate the ans.



Manager
Joined: 24 Nov 2010
Posts: 177
Location: United States (CA)
Concentration: Technology, Entrepreneurship

Re: : What is the probability that event E or event F or both w
[#permalink]
Show Tags
01 Mar 2011, 10:37
dreambeliever wrote: If the events are mutually exclusive then the prob = 0 I mean ans = 1 in case of mutually exclusive.



Intern
Joined: 03 Mar 2010
Posts: 37

Re: : What is the probability that event E or event F or both w
[#permalink]
Show Tags
18 Mar 2011, 04:29
If we agree that 1. (E OR F) means E, or F, or both will occur 2. (E AND F) means both will occur then we have (see MGMAT Guide 4 page 87) P(E OR F) = P(E) + P(F)  P(E AND F) Here P(E AND F) is not given, so the answer is E.
_________________
Hardworkingly, you like my post, so kudos me.



Manager
Joined: 05 Jan 2011
Posts: 124

Re: : What is the probability that event E or event F or both w
[#permalink]
Show Tags
18 Mar 2011, 06:05
bogos wrote: If we agree that 1. (E OR F) means E, or F, or both will occur 2. (E AND F) means both will occur then we have (see MGMAT Guide 4 page 87) P(E OR F) = P(E) + P(F)  P(E AND F) Here P(E AND F) is not given, so the answer is E. P(E OR F) = P(E) + P(F)  P(E AND F) is true if E and F are dependent events.However if they are independent Events P(E OR F) = P(E) + P(F) .Question does not provide information ..whether E and F are dependent/ independent event ...so it should be E



Intern
Joined: 03 Mar 2010
Posts: 37

Re: : What is the probability that event E or event F or both w
[#permalink]
Show Tags
18 Mar 2011, 08:00
The formula is always true. MGMAT just clarifies the point by seperating the two cases. In fact, we have: P(E AND F) = 0 if E and F are independent.
_________________
Hardworkingly, you like my post, so kudos me.



Senior Manager
Joined: 17 Mar 2011
Posts: 441
Location: United States (DC)
Concentration: General Management, Technology
GPA: 3.37
WE: Information Technology (Consulting)

Re: : What is the probability that event E or event F or both w
[#permalink]
Show Tags
18 Mar 2011, 10:18
Quote: P(E AND F) = 0 if E and F are independent. Not true, P(E AND F) = 0 if E and F are MUTUALLY EXCLUSIVE. To say that E and F are independent means only that the outcome of E has no effect on the outcome of F and vice versa. Quote: P(E OR F) = P(E) + P(F)  P(E AND F) is true if E and F are dependent events.However if they are independent Events P(E OR F) = P(E) + P(F) If they are independent events you still need the P(E and F) For example: If you flip two coins (coins 1 and 2) at the same time, and we call the event that coin 1 lands heads "E" and the event the coin 2 lands heads "F", what is P(E or F)? P(E) = .5 P(F) = .5 P(E or F) does not equal 1.



Manager
Joined: 31 Oct 2011
Posts: 230

Re: GWD #18 M32
[#permalink]
Show Tags
09 May 2012, 11:47
Independent probability
Ifor example, if two coins are flipped the chance of both being heads is [18]
Mutually exclusive If either event A or event B or both events occur on a single performance of an experiment this is called the union of the events A and B denoted as .
For example, the chance of rolling a 1 or 2 on a sixsided die is
This is from Wikipedia. I found this when I was searching for the explanation for this question. But I am still confused the difference between independent probability and mutually exclusive. To me, they sound the same. Help me understand them.



Manager
Affiliations: Project Management Professional (PMP)
Joined: 30 Jun 2011
Posts: 137
Location: New Delhi, India

Re: What is the probability that event E or event F or both will
[#permalink]
Show Tags
15 Jun 2012, 02:10
eybrj2 wrote: What is the probability that event E or event F or both will occur?
(1) The probability that event E will occur is 0.6 (2) The probability that event F will occur is 0.4 What is asked is the value of P(E)+P(F)+P(E union F) we cannot determine (E union F) combining 1 & 2 as well. Hence the answer is E
_________________
Best Vaibhav
If you found my contribution helpful, please click the +1 Kudos button on the left, Thanks



Manager
Joined: 13 May 2010
Posts: 111

Re: What is the probability that event E or event F or both will
[#permalink]
Show Tags
29 Oct 2012, 13:35
shouldn't this be P(e) + P(f) and so the answer C Why E?



Manager
Joined: 14 Jan 2013
Posts: 140
Concentration: Strategy, Technology
GMAT Date: 08012013
GPA: 3.7
WE: Consulting (Consulting)

Re: What is the probability that event E or event F or both will
[#permalink]
Show Tags
16 Jan 2014, 18:42
Hi Bunuel,
I am not clear why E is the answer...
we have to find P(E)+P(F) + P(EUF), so using Stm1 and Stm 2, we should be able to find.
i.e 0.6 +0.4 + ( 0.6x0.4)...
So, Isn't the answer should be C
Thanks



SVP
Joined: 06 Sep 2013
Posts: 1705
Concentration: Finance

Re: What is the probability that event E or event F or both will
[#permalink]
Show Tags
28 Jan 2014, 04:22
Mountain14 wrote: Hi Bunuel,
I am not clear why E is the answer...
we have to find P(E)+P(F) + P(EUF), so using Stm1 and Stm 2, we should be able to find.
i.e 0.6 +0.4 + ( 0.6x0.4)...
So, Isn't the answer should be C
Thanks I'm not Bunuel but I'm sure I can help P (A and B) = P(A) * P (B/A). That means the probability of B given that A happens. Now only way that the second term is equal to P(B) is if they are independent events, otherwise the probability will be affected. For instance if you have some balls to pick from and you remove some and don't replace them then successive probabilities will change right? So back to the question, Are they independent events? We just don't know this. Hope it helps brother Cheers! K PS. Just as a side note check also Mutually exclusive events in the GMAT Club Math Book just to be clear with those Probability concepts



Intern
Joined: 22 Jan 2014
Posts: 1

Re: What is the probability that event E or event F or both will
[#permalink]
Show Tags
28 Jan 2014, 05:34
Hi we have no information weather E and F are independent events. So we cant answer the question even by considering the two choices So ans should be E



Board of Directors
Joined: 17 Jul 2014
Posts: 2598
Location: United States (IL)
Concentration: Finance, Economics
GPA: 3.92
WE: General Management (Transportation)

Re: What is the probability that event E or event F or both will
[#permalink]
Show Tags
17 Mar 2016, 17:28
banksy wrote: What is the probability that event E or event F or both will occur?
(1) The probability that event E will occur is 0.6. (2) The probability that event F will occur is 0.4. we are asked P(E or F) + P(E and B) usually, if the two events are mutually exclusive, then: P(E) + P(F)=1.  and P(E or F)=1, and P(E and F)=0. if not, then: P(E or F) = P(E) + P(F) + P(E and F) and P(E or F)+P(E and F) = P(E) + P(F) moreover, it might be conditional probability... 1. P(E)=0.6, but we do not know anything about P(F), or about what kind of events these two are. Moreover, we do not know whether there are any relations between these two. not sufficient. 2. P(F)=0.4  same as 1. so no at this moment, we crossed A, B, and D. our chances of getting to the right answer increased considerably  probability 50% (see how I used probability even here? :D) ok, so it might appear that the two events are independent, since P(E)+P(F)=1. but what if we have a conditional probability? what if F can be chosen only if E is chosen? in this case, the probability of getting F is P(E)* # of successes/total outcomes left = 4/10 since we do not know the relationship between these two events, then we cannot give a definite answer. E



Director
Joined: 04 Jun 2016
Posts: 570

What is the probability that event E or event F or both will
[#permalink]
Show Tags
05 Aug 2016, 04:07
banksy wrote: What is the probability that event E or event F or both will occur?
(1) The probability that event E will occur is 0.6. (2) The probability that event F will occur is 0.4. REMEMBER TWO TERMS: 1) Mutually exclusive events (rolling and dice AND tossing a coin) INDEPENDENT of each other 2) Mutually non exclusive events (Rolling a Dice and getting a number less than 6 OR a prime number ; 2,3, 5 are less than 6 as well as prime) For two events Probability is defined in terms of Probability of First event ,Probability of second event ,Probability of both events and Probability of none of the events. P(E) + P(F) + P(E & F) + P(None) = 1 If the events are mutually exclusive, meaning that both events cannot happen together  than Probability of P(E and F) will be 0. But if events are not mutually exclusive then we must know the probability of none to calculate probability of both happening together Since neither the stimulus nor any of the options gives us P(None) , we cannot find the probability ANSWER IS E
_________________
Posting an answer without an explanation is "GOD COMPLEX". The world doesn't need any more gods. Please explain you answers properly. FINAL GOODBYE : 17th SEPTEMBER 2016. .. 16 March 2017  I am back but for all purposes please consider me semiretired.



Senior DS Moderator
Joined: 27 Oct 2017
Posts: 1199
Location: India
Concentration: International Business, General Management
GPA: 3.64
WE: Business Development (Energy and Utilities)

Re: What is the probability that event E or event F or both will
[#permalink]
Show Tags
07 Apr 2018, 06:41




Re: What is the probability that event E or event F or both will &nbs
[#permalink]
07 Apr 2018, 06:41






