A telephone survey of television viewers revealed the following information: 20 watch situation comedies; 19 watch reality shows; 27 watch movies; 19 watch movies but not reality shows; 15 watch situation comedies but not reality shows; 10 watch both situation comedies and movies; 3 watch all three; 7 watch none of these. (a) How many viewers were interviewed? (b) How many viewers watch comedies and movies but not reality shows? (c) How many viewers watch only movies? (d) How many viewers do not watch movies?
