We need to draw a tree diagram for the information given
The total is 400
120 in finance course
220 in a speech course
55 in both courses
Then we start for a tree for the given number
Then to make the tree for probability we will divide each number by a total 400
Then the probability of finance only is 65/400
The probability of speech only is 165/400
The probability of both is 55/400
The probability of neither is 5/400
The probability of finance or speech is 285/400
