There are 50 students going on a class trip. 35 are student athletes and 5 are left-handed. In the student athletes group, 3 are left-handed. What is the probability that one of the students on the trip is an athlete or is left-handed?
There must be 2 non-athletes who are left-handed. Hence probability of randomly selecting student who is athlete or left-handed (or both) is (35+2)/50 = 0.74