Probability Question 136
Question: A coin is tossed 10 times. The probability of getting exactly six heads is
[Kerala (Engg.) 2002]
Options:
A) $ \frac{512}{513} $
B) $ \frac{105}{512} $
C) $ \frac{100}{153} $
D) $ {}^{10}C_6 $
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Answer:
Correct Answer: B
Solution:
p = P (getting a head) $ =\frac{1}{2},q=\frac{1}{2}. $
Required probability = P(six successes) $ ={{}^{10}}C_6{{( \frac{1}{2} )}^{6}}{{( \frac{1}{2} )}^{4}} $
$ =\frac{10!}{6!4!}.\frac{1}{2^{10}}=\frac{105}{512} $ .