Answers

2015-05-09T13:53:00+05:30
This is a binomial distribution with n=8 and p=1/2
Pr(X=k)=\binom{n}{k}p^k(1-p)^{n-k}

Pr(X=6)=\binom{8}{6}(1/2)^6(1-1/2)^{8-6}=\frac{7}{64}
Pr(X=7)=\binom{8}{7}(1/2)^7(1-1/2)^{8-7}=\frac{1}{32}
Pr(X=8)=\binom{8}{8}(1/2)^8(1-1/2)^{8-8}=\frac{1}{256}

Pr(X\ge{6})=Pr(X=6)+Pr(X=7)+Pr(X=8)

=\frac{7}{64}+\frac{1}{32}+\frac{1}{256}

=\boxed{\frac{37}{256}}
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2015-05-09T14:11:14+05:30


P(H)= 37/256

This is the probability. You may take P>5

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