help me with this question, kindly give a clear answers step and the formula used.

QUESTION 3 a) Define random variable and give ONE (1) example of discrete random variable. (2 marks) b) The probability distribution of X is shown below. X = X 2 3 4 5 P (X = X) 0.15 m n 0.35 i) Given that the probability of X is not more than 3 is 0.5, find the value of m and n. (4 marks) ii) Compute the value of P(2