T1.9 The proportions of freshmen (F), sophomore (P), junior (J), and senior (S) students in a 4-year college are given in the table. Assuming that the ranks of two randomly selected students are...

T1.9

The proportions of freshmen (F), sophomore (P), junior (J), and senior (S) students in a 4-year college are given in the table.

Assuming that the ranks of two randomly selected students are independent, find the probability that

a) their ranks are the same

b) exactly one of the students is a senior