Answer to Question #142124 in Statistics and Probability for qwerty

Question #142124

2. In the senior year of a high school graduating class of 100 students, 42 studied mathematics, 68 studied psychology, 54 studied history, 22 studied both mathematics and history, 25 studied both mathematics and psychology, 7 studied history but neither mathematics nor psychology, 10 studied all three subjects, and 8 did not take any of the three. Randomly select a student from the class and find the probabilities of the following events:

(a) A person enrolled in history takes all three subjects
(b) A person enrolled in history but not in mathematics and psychology

Expert's answer

(a) 10/100 = 0.1

(b) 7/100 = 0.07