Answer:
5/12 of the students are freshmen.
Explanation:
Let n represent the total number of students.
Then (1/6)n are seniors; (2 1/2)(1/6)n are freshmen, or
(1/6)n are seniors and 5/12 are freshmen. This comes from multiplying 2.5 by 1/6: we get .416666..., which is equivalent to 5/12.