Number of students in senior class is 130
<em><u>Solution:</u></em>
Given that Every student in the senior class is taking history or science
85 of them taking both history and science
106 seniors takes history
109 seniors takes science
To find: number of students in senior class
Let A be the set of the students of the senior class that take history
Let B be the set of students of senior class that they science
The number of students in senior class is given by:
Where,
A = 106 and B = 109 and |A n B| = 85
Thus number of students in senior class is 130