To find the ratio of the number of empty seats to the total number of seats, we first identify the total number of seats and the number of empty seats.
- Total number of seats = 50
- Number of empty seats = 40
Now, we can set up the ratio of empty seats to total seats:
\[ \text{Ratio} = \frac{\text{Number of empty seats}}{\text{Total number of seats}} = \frac{40}{50} \]
Next, we simplify the fraction:
\[ \frac{40}{50} = \frac{4}{5} \]
Thus, the ratio of the number of empty seats to the total number of seats is \( \frac{4}{5} \).