In a group of students 25 smoke cigarettes 60 drink alcohol

In a group of students, 25% smoke cigarettes, 60% drink alcohol, and 15% do both. What is the probability that a randomly selected student from the group has at least one of these

Solution

probability of cigarette=25/100=0.25

probability of alcohol=60/100=0.6

probability of both=15/100=0.15

probability that they atleast drink or smoke= 0.25+0.6-0.15=0.7