【问一道英文数学题目(美国高中水平的)Inasurveyof63people,23peoplesubscribedtomagazineA,21peoplesubscribedtomagazineB,and17subscribedtomagazineC.Foranytwoofthemagazaines,4peoplesubscribedtobothmagazinesb】
问一道英文数学题目(美国高中水平的)
Inasurveyof63people,23peoplesubscribedtomagazineA,21peoplesubscribedtomagazineB,and17subscribedtomagazineC.Foranytwoofthemagazaines,4peoplesubscribedtobothmagazinesbutnottothethridmagazine.If5peopleinthesurveydidnotsubscribetoanyofthreemagazines,howmanypeoplesubscribedtoallthreemagazines?
怎么我一直做都是负数呢?