1) The records of 100 students show the following courses taken:
53 students took History
41 students took Marketing
48 students took Writing
18 students took History and Marketing
21 students took Marketing and Writing
7 students took all 3 courses
9 students took none of these courses
Answer the following questions. Show how you obtained your solution.
a) How many students took Marketing and Writing, but not History?
b) How many students took only History?