In a group of 150 people, 90 have an age of more 30 years, and the others have an age of less than 20 years. If a person is selected at random from this group, what is the probability the person's age is less than 20?
Answers
A) 0.4 B) 0.5 C) 0.65 D) 0.75 E) 0.85

Rationale: "number of people whose age is less than 20 is given by 150 - 90 = 60 probability p that a person selected at random from the group is less than 20 is given by 60 / 150 = 0.4 correct answer a"
Answer: A