CIL 2026 | System | Question: 26

Question

Which of the following is not a property of a discrete random variable $\mathrm{X}$, that takes any value from $0,1,2, \ldots, \mathrm{n}$?

• A. $\mathrm{P}(\mathrm{X}=\mathrm{n})<0$
• B. $\Sigma \mathrm{P}(\mathrm{X}=\mathrm{x})=1$, the summation is taken over all possible values of $\mathrm{X}$
• C. If $\mathrm{A}$ and $\mathrm{B}$ are two disjoint subsets of $\{0,1,2, \ldots, n\}$ then $\mathrm{P}(\mathrm{A}+\mathrm{B})=\mathrm{P}(\mathrm{A})+\mathrm{P}(\mathrm{B})$
• D. For any possible value of $\mathrm{X}$, $\mathrm{P}(\mathrm{X}=\mathrm{x}) \geq 0$