In a graduate physics course, 70 percent of the students are male and 30 percent of the students are married. If two-sevenths of the male students are married, what fraction of the female students is single?
Choose the correct choice:
A) 2/7  B) 1/3  C) 1/2  D) 2/3  E) 5/7
Let the universal set be X = {all students in the graduate physics course}, such that n(X) = 100   It will contain 2 mutually exclusive sets; M (all male students) &amp; F (all female students), where n(M) = 70, n(F) = 30   Now 2/7 of all male students are married, implying their number = 20.   However the total number of married students = 30, implying 10 married females.   Therefore 20 single females; = 2/3 of total females.   ANSWER:2/3
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In a graduate physics course, 70 percent of the students are male and 30 percent of the students are married. If two-sevenths of the male students are married, what fraction of the female students is single?