Question

There are three sections of English 101. In Section​ I, there are 20 students, of whom 6 are mathematics majors. In Section​ II, there are 40 students, of whom 4 are mathematics majors. In Section​ III, there are 25 students, of whom 5 are mathematics majors. A student in English 101 is chosent at random. Find the probability that the student is from Section III given that he or she is a mathematics major.

Answer 1

Total mathematics majors =6+4+5=15

Mathematics majors in section III =5

The probability that the student is from Section III given that he or she is a mathematics major is