If the probability function of a random variable $\mathrm{X}$ is given by $P(\mathrm{X}=k)=\frac{3^{c k}}{k…
If the probability function of a random variable $\mathrm{X}$ is given by $P(\mathrm{X}=k)=\frac{3^{c k}}{k !}$ for $k=1,2,3, \ldots$ (where $c$ is a constant), then $c=$