The number of students are 235.
Number of seats in a row is 28.
Determine the number of rows required to sit 235 graders with 28 in each row.
[tex]\begin{gathered} \frac{235}{28}=\frac{224+11}{28} \\ =8+\frac{11}{28} \end{gathered}[/tex]So, 8 rows in addition of one additional row of 28 seats to sit 11 more students is required. So minimum number of row required to sit 235 students are 9.
Answer: 9 rows.