SECTION A
The following table shows the distribution of the numbers of hours talking on mobile phones by a group of students on a certain day. Number of hours talking on mobile phone1234Number of students8ab12 It is given that a and b are positive numbers. (a) Find the least possible value and the greatest possible value of the median of the distribution. (b) If b =2 and the inter-quartile range of the distribution is 3, how many possible values of a are there? Explain your answer.
(5 marks)