To find the unit rate of seats per row, you divide the total number of seats by the number of rows.
Given:
- Total seats = 39
- Total rows = 3
Now, calculate the seats per row:
\[ \text{Seats per row} = \frac{\text{Total seats}}{\text{Total rows}} = \frac{39}{3} = 13 \]
Therefore, there are 13 seats per row.