Answer:
39 seats are not being used in the auditorium.
Explanation:
We have bee given the total number of seats:
In middle school auditorium are 342
Seats used by teachers are 75
And seats used by students are
![(2)/(3)\text{of the seats}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ibeh1aydqzbcjx5qgiyqkmijxg6kuf5g43.png)
And
seats used by students
That means 228+75=303 seats are used
We need to calculate seats not being used which is equal to
Total seats minus seats used =342-303 =39 seats remain unused.