Twenty percent of the population of Springhill has been to Italy at least once in the last five years, and thirty percent of the population of Springhill has been to France at least once in the last five years. Ttherefore, half of the population of Springhill has been to Europe at least once in the last five years. The argument is faulty because it ignores the possibility that ['some of the population of Springhill has been neither to Italy nor to France in the last five years', 'none of the population of Springhill has been either to Italy or to France more than once in the last five years', 'some of the population of Springhill has been both to Italy and to France in the last five years', 'some of the population of Springhill has been either to Italy or to France in the last five years, but not to both']