r = 3

There are (5 + R) females and (15 R) males in a tutorial group. Suppose two students are selected from the tutorial group one after the other without replacement as the class representatives and X is the number of female students selected. (i) Construct a discrete probability distribution for the random variable X. Correct your probabilities to 4 decimal places. (6 marks) (4 marks) (ii) Find the expected value of X. R+5 In a college, the probability for any student to be ABSENT from the exam is Suppose 5 students are selected from the college randomly. 100 (i) Find the probability that more than 3 students among the 5 selected students are PRESENT in the exam. Correct your answer to 4 decimal places. (6 marks) Suppose Y is the number of students ABSENT from the exam among the 5 selected students. Find the standard deviation of Y. (4 marks)