At a certain university, 60% of undergraduate students are male, and 40% are female. Ten percent of

Question:

At a certain university, 60% of undergraduate students are male, and 40% are female. Ten percent of females change their majors at least once. Overall, 30% of students change their majors at least once.
a. Find the probability that, given a randomly selected student who changes majors, the student is a female.
b. What percentage of males change their majors at least once?