Q. 22

# Mark (√) against the correct answer in each of the following:

A coin is tossed 5 times. What is the probability that tail appears an odd number of times?

A.

B.

C.

D.

Answer :

Using Bernoulli’s Trial P(Success=x) = ^{n}C_{x}.p^{x}.q^{(n-x)}

x=0, 1, 2, ………n and q = (1-p)

As the coin is tossed 5 times the total number of outcomes will be .

And we know that the favourable outcomes of getting the odd tail number of times ,successes will be, getting a tail

The probability of success is and of failure is also

^{5}C_{1}()^{1}()^{4} +^{5}C_{3}()^{3}()^{2} +^{5}C_{5} ()^{5}()^{0}

⇒

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