The probability of no successes in 25 is \(\displaystyle \left( {0.9} \right)^{25}\).
The probability of exactly one success in 25 is \(\displaystyle \left( {25} \right)\left( {0.1} \right)\left( {0.9} \right)^{24}\).
Thus the of two or more successes in 25 is \(\displaystyle 1 - \left[ {\left( {0.9} \right)^{25} + \left( {25} \right)\left( {0.1} \right)\left( {0.9} \right)^{24} } \right]\)
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.