A special case of the negative binomial distribution, where r=1r=1r=1. Denoted by g∗(x;p)g^*(x;p)g∗(x;p). Memoryless. P(x)=p(1−p)x−1P(x) = p(1-p)^{x-1} P(x)=p(1−p)x−1 Here: ppp - probability of success in a single trial Mean μX=1p\mu_X = \frac{1}{p} μX=p1 Variance Vx=1−pp2V_x = \frac{1-p}{p^2} Vx=p21−p