Discrete Structure

QUESTION 4 An advertising agency finds that, of its 170 clients, 115 use Television, 110 use Radio and 130 use Magazines. 85 use Television and Magazines, 75 use Television and Radio, 95 use Radio and Magazines, 70 use all the three. (i) How many use only Radio? (ii) How many use only Television? (iii) How many use Television and Magazine but not radio? [12 marks]