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08 Dec 2014, 06:19
Kudos
Bookmarks
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
45%
(medium)
Question Stats:
66% (01:51) correct
34%
(02:09)
wrong
based on 326
sessions
History
Date
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What is the probability of tossing a coin five times and having heads appear at most three times?
A) 1/16
B) 5/16
C) 2/5
D) 13/16
E) 27/32
A) 1/16
B) 5/16
C) 2/5
D) 13/16
E) 27/32
08 Dec 2014, 06:29
Kudos
Bookmarks
I think it is C. Total number of outcomes 25. 3 out 5 is (5!)/(3!2!) = 10. Hence probability is 10/25= 2/5.
08 Dec 2014, 07:50
Kudos
Bookmarks
What is the probability of tossing a coin five times and having heads appear at most three times?
A) 1/16
B) 5/16
C) 2/5
D) 13/16
E) 27/32
Total number of outcomes of coin tossed 5 times = \(2^5\) = 32
Number of outcomes with all heads = 1
Number of outcomes with 4 heads =\(C^5_1\)=5
Therefore number of favorable outcome (at most three heads) = 32-(5+1) = 26
Probability (heads appear at most three times) =\(\frac{26}{32} = \frac{13}{16}\)
Answer:D
A) 1/16
B) 5/16
C) 2/5
D) 13/16
E) 27/32
Total number of outcomes of coin tossed 5 times = \(2^5\) = 32
Number of outcomes with all heads = 1
Number of outcomes with 4 heads =\(C^5_1\)=5
Therefore number of favorable outcome (at most three heads) = 32-(5+1) = 26
Probability (heads appear at most three times) =\(\frac{26}{32} = \frac{13}{16}\)
Answer:D
