Probability of independent not mutually exclusive events I am wondering if I am doing this right. If an event has a probability of happening of $0.9\%$, what is the probability it will happen if it is repeated $50$ times. I have tried to calculate this with this formula:


  $1-0.009^{50}$ 


Which gives $1$, so what I am wondering is it really true that if an event has a chance of only $0.9\%$ of happening once, if repeated $50$ times it will happen for sure, or have I used the wrong formula to calculate this?
$0.009^{50}$ is the probability the event happens $50$ times out of $50$
$1-0.009^{50}$ is the probability the event happens fewer than $50$ times out of $50$
$(1-0.009)^{50}$ is the probability the event happens $0$ times out of $50$
$1-(1-0.009)^{50}$ is the probability the event happens more than $0$ times out of $50$
Because your calculator can only calculate up to certain precision. For a value that is too small, say $0.009^5$ in your case, the calculator regards it as $0$.