geometric distribution

how many times do you have to do the trial to get at least one success
constituents p is the probability of one individual success x is the number of trials requirements \begin{equation} P(X = x) = \left(1-p\right)^{x-1} p \end{equation}
which represents the probability of getting a success on the x trial
additional information \begin{equation} \mathbb{E}[X] = \frac{1}{p} \end{equation}