Of all the students in a certain dormitory, 1/2 are first-year students and
the rest are second-year students. If 4/5 of the first-year students have not
declared a major and if the fraction of second-year students who have declared a
major is 3 times the fraction of first-year students who have declared a major,
what fraction of all the students in the dormitory are second-year students who
have not declared a major?