Answer:
B. 45%
Explanation:
The total number of seats in the auditorium = 400
Number of occupied seats = 220
Thus, the number of unoccupied seats = 400-220 = 180
So, the percentage of seats that were unoccupied will be:
[tex]\begin{gathered} =\frac{180}{400}\times100 \\ =\frac{180}{4}\% \\ =45\% \end{gathered}[/tex]The correct choice is B.