Team A plays two matches each with Team B and Team C. In any match, the probability of different outcome for Team A is given below:
Outcome Win / Loss / Draw
Probability 0.5 / 0.45 / 0.05
Points 2 / 0 / 1
Outcome of all the matches are independent of each other.
Q1: What is the probability of Team A getting at least 7 points in the contest? Assume Team B and Team C play 2 matches.
A. 0.025
B. 0.0875
C. 0.0625
D. 0.975
E None of these
Q2. What is the probability of Team C getting at least 4 points? Assume Team C and Team B play 2 matches.
A. 0.2025
B. 0.0625
C. 0.0425
D. 0.050
E. Can't be determined
My Doubts:
In question 1 the statement "Assume Team B and Team C play 2 matches" what information is this statement providing.
In question 2: "Assume Team C and Team B play 2 matches" is it not conflicting with the information in the us. Moreover the table only shows the probability of win or lose for Team A. So can I say it can't be determined?
My Solution Approach:
For Team A to have at least 7 points, out of total 4 matches that it plays with Team B and Team C. It should either Win 3 and draw 1 or Win all of them.
So the first case of winning all matches:
W X W X W X W = 0.5 X 0.5 X 0.5 X 0.5 = 0.0625
Second case, Winning 3 draw 1:
W X W X W X D = 0.5 X 0.5 X 0.5 X 0.05 = .00625 x 4 = .025 (as it is possible in following 4 ways)
W W W D
W W D W
W D W W
D W W W
So probability of getting at least 7 points = .025 + .0625 = 0.0875
Answer B;
Solution 2:
Can't determine as there is no information for the probability of outcome for the match between B & C. Is it correct?
Please advise. Thank you.
Combinatorics: Help Required
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- Mike@Magoosh
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Dear Dblooos,
I'm happy to respond.
I agree with your work, and agree that the answers should be
1) (B)
2) (E)
I believe this is what you meant.
Here's a blog with some additional challenging problems in probability:
https://magoosh.com/gmat/2014/gmat-advan ... -problems/
Enjoy!
Mike
I'm happy to respond.
I agree with your work, and agree that the answers should be
1) (B)
2) (E)
I believe this is what you meant.
Here's a blog with some additional challenging problems in probability:
https://magoosh.com/gmat/2014/gmat-advan ... -problems/
Enjoy!
Mike
Magoosh GMAT Instructor
https://gmat.magoosh.com/
https://gmat.magoosh.com/