Question

How do you find the probability of at least two successes when `n` independent Bernoulli trials are carried out with probability of success `p`?

Answer 1

`=1 - (1-p)^(n-1)*(1+p(n-1))`

Explanation:

`=1 - P["0 successes"] - P["1 success"]`
`=1 - (1-p)^n - n*p*(1-p)^(n-1)`
`=1 - (1-p)^(n-1)*(1-p + n*p)`
`=1-(1-p)^(n-1)*(1+p(n-1))`