There are three sections of English 101. In Section I, there are 25 students, of whom 6 are mathematics majors. In Section II, there are 35 students, of whom 4 are mathematics majors. In Section III, there are 40 students, of whom 7 are mathematics majors. A student in English 101 is chosen at random. Find the probability that the student is from Section I, given that he or she is a mathematics major.