At a certain university, 30% of the students major in math. Of the students majoring in math, 60% are males. Of all the students at the university, 70% are males.
a) What is the probability that a student selected at random in the university is male and majors in math?
b) What is the probability that a randomly selected student in the university is female or majors in math or both?
Based upon the information you provided, out of every 100 students you have this breakdown:
male, math major: 18
female, math major: 12
male, non-math major: 52
female, non-math major: 18
b) female: 30%
math major (either sex): 30%
female math major: 12%
so for b), you just add them up to get 72%?