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given for one ticket, probability to win is 1/9, what is the probability og winning twice if we bought 10 tickets

 Nov 17, 2016
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given for one ticket, probability to win is 1/9, what is the probability og winning twice if we bought 10 tickets

 

\(\begin{array}{|rcll|} \hline && \displaystyle \binom{10}{2} \cdot \left(\frac{1}{9} \right)^2 \cdot \left(\frac{8}{9}\right)^8 \\\\ &=& \displaystyle \frac{10}{2}\cdot \frac{9}{1} \cdot \frac{8^8}{9^{10}} \\\\ &=& \displaystyle \frac{45\cdot 8^8}{9^{10}} \\\\ &=& \displaystyle \frac{754\, 974\, 720}{3\, 486\, 784\, 401} \\\\ &=& 0.21652463507 \qquad (21.65\ \%) \\ \hline \end{array}\)

 

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 Nov 17, 2016

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