Hi folks,
one problem for you. How do you solve this?
Event A: probability 2/3
Event B: Probability 2/3
Event C: Probability 2/3
Event D: Probability 1/3
What is the probability that none of the events listed above occur?
Probability problem
This topic has expert replies
-
- Master | Next Rank: 500 Posts
- Posts: 353
- Joined: Sat Jan 20, 2007 1:29 am
- Location: Italy
- Thanked: 7 times
- GMAT Score:720
Beat The GMAT - 1st priority
Enter a top MBA program - 2nd priority
Loving my wife: MOST IMPORTANT OF ALL!
REAL THING 1 (AUG 2007): 680 (Q43, V40)
REAL THING 2 (APR 2009): 720 (Q47, V41)
Enter a top MBA program - 2nd priority
Loving my wife: MOST IMPORTANT OF ALL!
REAL THING 1 (AUG 2007): 680 (Q43, V40)
REAL THING 2 (APR 2009): 720 (Q47, V41)
- Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
To solve this, we need more information. Let me rephrase the question that I think you meant to ask:mjjking wrote:Hi folks,
one problem for you. How do you solve this?
Event A: probability 2/3
Event B: Probability 2/3
Event C: Probability 2/3
Event D: Probability 1/3
What is the probability that none of the events listed above occur?
If the chart above shows the probability of independent events A, B, C and D occuring, what's the probability that none of the 4 events occurs?
If we want to know the probability of MULTIPLE independent events occuring (or not occuring), we MULTIPLY the individual probabilties.
Let's start by calculating the probability of each event NOT occuring using the handy "1 minus" formula:
Prob (event occuring) + Prob (event not occuring) = 1
or
1 - Prob (event occuring) = Prob (event not occuring)
So, the probability of each event NOT occuring:
Event A: 1 - 2/3 = 1/3
Event B: 1 - 2/3 = 1/3
Event C: 1 - 2/3 = 1/3
Event D: 1 - 1/3 = 2/3
And the probability of ALL 4 events NOT occuring is:
1/3 * 1/3 * 1/3 * 2/3 = 2/81
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course