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) = nCx.px.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 
5C1(
)1(
)4 +5C3(
)3(
)2 +5C5 (
)5(
)0
⇒ 
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