8. The discrete random variable X has probability function given by () x = 1, 2, 3, 4, 5, p(x) = C x =6, otherwise, where c is a constant. Determine the value of c and hence the mode and mean of X. 12. A team of three is to be chosen from four boys and five girls. If X is the random variable 'the number of girls in the team', find (a) E(X), (b) E(X ), (c) Var(X). (b) A bag contains five identical discs, two of which are marked with the letter A and . ... " . three with the letter B. The discs are randomly drawn, one at a time without replacement, until both discs marked A are obtained. Show that the probability that three draws are required is to- Given that X denotes the number of draws required to obtain both discs marked A, copy and complete the following table. Value of X 2 3 Probability of X To Evaluate (i) E(X), (ii) E(X]) (iii) the variance of X